"We pretty much done here, doc?"

Hank McCoy, otherwise known as the mutant outlaw Beast of the X-Men, chuckled. "Not quite yet, Logan. There's just a few more tests to run. I still can't believe that, in all the years you've been on the team, you've never had a comprehensive medical examination."

The grizzled loner grimaced. They were down in the X-Mansion's science lab. Ordinarily that wouldn't be so bad-he trusted Beast to know his stuff-but for some reason Hank had insisted he be completely undressed for this occasion. So there he was laying on the examination table, butt-naked in all his rugged, macho glory, while Hank ran all sorts of scans and tests on him. And without so much as a privacy screen in case somebody wandered in.

Not that Wolverine was exactly modest. But if he was going to be spending time "getting back to nature" he preferred to do it out in the wilderness rather than a cold sterile lab. Too many bad memories.

"Never much liked doctors poking and prodding at me," Wolverine grumbled. "It's how I got these bones of mine in the first place." He held out a hairy, muscled arm, and three razor-sharp claws sprang from his knuckles with a ringing snikt.

"Yes well, your adamantium skeleton is one of the reasons I'm examining you," Hank told him reassuringly, looking over his charts. For himself the mutant doctor had donned a white lab coat over his usual costumed speedo, though casually left open to show his powerful, almost ape-like physique, all covered in blue fur. He adjusted his spectacles. "The bonding process used is fascinating, simply fascinating."

"I think of it more like a curse. Never asked for it, never wanted it."

"Yes, but still . . . and to think, none of it would have been possible without your mutant healing factor, either," Beast said, lost in keen scientific interest. But then he shook his head as another thought occurred to him. "Oh, I'm going to need a tissue sample. Would you mind turning over, Logan?"

Wolverine looked at him warily, but obliged. He had the feeling he knew what was about to happen, because why else have him lay face-down? True to form, in the next instant Beast affirmed his suspicions by jabbing a needle straight into the meatiest part of his ass. Still, it surprised him being done without warning, and he reflexively jerked on the table. "Yeow! Watch where you stick that thing, doc!"

"Apologies, Logan. A few of my patients have a habit of tensing up when there are needles involved. It's not a problem for some, but others, like Colossus-who can form literal buns of steel, if you'll pardon the expression-can make my job difficult. It's often best to catch them unawares."

"Yeah, well I ain't Colossus," Wolverine told him, disgruntled. "For one, my ass is a lot hairier than the Russkie's."

"Indeed." Beast chuckled as he carefully withdrew the point from the wounded buttock. "I daresay you could even give my own hirsute derriere a run for it's money. You haven't been dipping into any mutagenic serum lately, have you?" he asked, referring to the formula which had initially triggered the transformation to his familiar simian self.

"Not last time I checked."

The two shared a smirk, before Beast looked back down at Wolverine's ass, strangely transfixed by the sight. The small hole his needle had made-it was already filling in. Another moment, and it was gone as if it had never existed at all. Beast poked a clawed fingertip at the spot in wonder. "Speaking of your healing factor . . . have there ever been any serious tests to gauge its effectiveness? How serious an injury it can handle, and how quickly? Things like that?"

Wolverine shifted a bit, grimacing at his teammate poking his butt. "It's saved my life more times than I can count. That's good enough for me."

"Yes, but you've never really tested it, to find its limits?"

"I told you, doc. I don't generally like needles."

"Yes, but . . . " he stopped, unsure how to go on. After all, one of the primary purposes of the Institute was to to help mutants learn more about their powers, yet Wolverine had no interest in learning about his own. Beast mulled, then his gaze wandered back to the perfectly round, muscled curve of Wolverine's posterior. An idea began to form in his head. A perverse, ludicrous idea. One that was so gloriously absurd he had no choice but to try it.

"Logan, what if I told you I could perform a more . . . informal test? No more needles involved, I promise."

Wolverine considered. "What'd ya have in mind, bub?"

...

He would soon regret asking.

Wolverine found himself in a strange new position. While Beast sat on the edge of the table, Wolverine had been instructed to stand, and then tip forward across his legs. That had placed him over the overgrown fuzzball's lap like a kid being taken out to the woodshed, his hairy, still naked, backside perched over a knee so it was raised up good and high for a licking. It had only startled him when the goofball of a scientist raised his hand and actually started doing it.

"Hey, Hank . . . "

"Yes, Logan?"

"Are you . . . spanking me?"

Hank let out an awkward chuckle. "I suppose that is what it would appear to be to you."

"I'm pretty flamin' sure that's how it'd look to anyone!" Wolverine exploded, his rear end jerking under the stinging slaps. He moved to rise, but was cut off-by another smack to his ass, much harder this time. "Argh!" he grunted out as he fell back across Beast's knees.

Beast wasted no time in pinning him there. "Now Wolverine, consider it logically. The best way to test your healing factor is to see it in action, correct? Hence, we must give it something to heal. That, plus the gluteus maximus serving a non-vital role on the body yet still filled with muscular tissue and nerve endings makes it the logical choice for testing your powers by . . . well, by spanking you, as you so eloquently stated."

Wolverine bristled. "I'm about ta start stating my eloquence in a lot sharper manner, if you get my point, unless you-Ow!" He grunted as Beast's paw once more landed. The guy had always had big, sturdy hands thanks to his mutation. He was sure putting them to good use now. "Ngah! You sunova-"

"Shush, please." Beast silenced him with another firm round of spanks. "I'm trying to take notes."

He looked down in awe at the large handprint he'd left on Logan's hard, unyielding buttock. While it had started out red directly on forming, after a handful of moments the color quickly faded to a dull, rosy pink. Perhaps ten seconds later, and even that had faded away completely, as if Beast had never used his brute strength to give Wolverine a harsh whack right across his naked posterior. He tested his findings with another spank, this one to the opposite cheek, and watched that mark fade away as well.

"Remarkable," he breathed.

"Remarkable I haven't minced ya yet . . ." Wolverine muttered, hanging over his lap while feeling like a slab of meat.

"Come now, Logan." Beast gave his buns a pat. "Surely you of all people can handle a little pain-in the name of science?"

He snorted. "I can take a lickin' with the best of 'em, but that doesn't-"

"And since this surely isn't the first time you've ended up in this position over the years . . . "

"Hey! What's that supposed ta mean!?"

The mutant scientist chuckled. "Only that you can surely bear the discomfort if it will help us get a solid understanding of your powers," he assured him, though privately he was putting together a list of villains who might have punished Wolverine's bottom over his infamously long and checkered past.

Wolverine huffed as he thought about it. "Fine . . . but you owe me a round o' brews at Harry's after this, fuzzball."

Beast grinned wide. "You've got yourself a deal!"

"Good, just don't make this a habit or nothing-yah!" Wolverine jerked again as Beast's broad hand collided with his grizzled ass. This time the blue mutant took a stopwatch out from his lab coat, and timed the length it took for the stinging print to fade. After making a note of that he raised his powerful, ape-like arm again, this time depositing two of his firm slaps, one on each cheek.

"Nngh!"

Again, Beast timed how long the marks took to fade from the clenched surface of Wolverine's hairy backside. "Fascinating," he murmured. He continued on in that fashion for a few minutes, gradually increasing the number of swats he dealt with each volley. He was testing to see if higher damage adjusted how Wolverine's healing factor worked, and if there was a specific cutoff point where it went into a form of fast healing 'overdrive', as he'd long hypothesized.

"Hnng! Yeah, thrilling," Wolverine said drily. "How much longer you plan on whipping my tail here, bub?"

"Logan, I'm not sure you grasp the full magnitude of my findings. Do you realize, for instance, that by this point in a similar flagellation, Bobby Drake's posterior would be red, hot and sore all over? Yet after only a few moments of recovery yours is looking as fresh as when I first took you over my knee," he marveled, giving it another swat. "Good as new, in fact!"

"Oof!" Wolverine grunted at the broad spank, but gave a half-smirk. "Iceman, huh? Why am I not surprised."

The blue doctor's eyes twinkled. "The amount of pranks Bobby pulls, you think he could escape punishment forever?"

"The more I hear, the more I approve."

"Yes, well . . . " Beast met Wolverine's rump with another heavy swat. "It's not Bobby's many well-deserved spankings I'd like to discuss right now, but your own. Brace yourself Logan, I'm going to test if there's any point where I can 'overload' your healing factor. I think . . . fifteen minutes to start."

Wolverine's brows furrowed. "Fifteen minutes? Fifteen minutes of wha-YEARRGH!" He suddenly yelped as Beast's palm struck him right at the apex of his ass, the muscled buttocks rippling under the force.

"Yes. Fifteen minutes of solid, relentless smacks should give me a solid baseline for use in future tests," Beast explained, adjusting his grip around Wolverine's nude waist to keep him from twisting away while his other hand hammered away at the startled man's backside.

"Yeargh! H-Hold up, Hank! This isn't-Yeowwww!" Wolverine jerked and thrashed at the truly savage beating he was getting. Hank was slamming his blue hand down with full, bruising force on his ass. A normal man might have broken a tail bone or worse from the impacts, but Hank had evidently been spending his time in the preliminary tests observing just how much Wolverine could take. Those findings were now put to painful use as he skillfully reddened the bucking, hair-strewn globes.

"Apologies again, Logan, but it's the same principle as the needle . . . If I told you what I was doing before the start, it might've colored the results."

"The same way you're coloring my flamin' ass!?" Wolverine retorted, flinging an arm back to shield his rump. But, in a display of his own incredible reflexes and agility, Beast caught his wrist before it came close and instead pinned it against Logan's bare back, deftly turning the direction of his sheathed claws to the side too, just in case.

"Trust me, Logan! This is for . . . your own . . . good!" Beast huffed, struggling to hold his indignant teammate in place while continuing to pummel his squirming ass. "Once you see the results of my findings, I'm confident you'll see that!"

Wolverine might have replied, but the hearty swats to his backside were quickly overcoming his healing factor's abilities to keep up with, and the snarling mutant had to fight not to enter a berserker state as his buttocks wriggled and blistered. He let out a guttural howl instead. "Aooowwww!"

...

Fifteen minutes later, an exhausted Wolverine lay slumped over Beast's lap, his ass a red battlefield of welts, bruises, and blisters. He'd kicked and writhed until the last second, but with the final smack to his sore glutes he'd at last succumbed to the burn and collapsed across his brawny teammate's knees.

"Is it . . . is it over?" he gasped.

Beast clicked his stop-watch. "Yes, that just about it does it. Now all we do is wait to see how long it takes your, ahem, hindquarters to recover. Then we'll be ready to start phase 2. I'm thinking perhaps increasing the time to twenty minutes for the next session . . . Wolverine? Wolverine, what are you doing!?"

Wolverine had gotten up with a snort. Getting a grip on Beast's upper arm, he pulled the surprised doctor down off the examination table. He then, with a pained grunt, gingerly set his own red, bare ass on the table, settling his weight on it with a wince. One hard yank, and Beast was across his legs.

"Nothing, bub. I just got an idea we can do while we wait."

"Ummm?" Beast asked in trepidation.

He gasped as his labcoat was then flipped up over his head, blinding him like a little kid. "Hey!" It also uncovered his backside, the round and muscled furry spheres barely concealed by a tight speedo. He wiggled in agitation as Wolverine extended an adamantium claw, but then quickly stilled as he felt the point slice, very slowly, down the tight middle seam of his trunks, right along Beast's butt crack. Wolverine then took hold of both sides and ripped the speedo apart to expose his beefy blue mounds.

"Gah! L-Logan! I must insist-!"

Logan reached over to his discarded possessions and rifled through them, before calmly taking out a match and flicking it across one of Hank's fuzzy buttocks. He used the flame it sparked to light a cigar, which he puffed as Hank squirmed indignantly over his lap. "Don't experiments need a control? We can't tell how good my healing factor is, unless we compare it to somebody else's, right? Somebody like . . . yours."

"W-Well now, that's-"

The grizzled mutant raised his hand, and smirked nastily. "Fifteen minutes, bub."