I do not own Gravity Falls.

When Bill had seen Mabel walking around, he had walked up to the girl with the intent of being with his favorite mortal. He had not expected for a pig to be pushed into his arms, the girl quickly explaining that she was going on a day trip with her brother and great uncle and that she needed someone to watch her beloved Waddles while she was gone. When he was about to speak against the prospect, he didn't manage to do more than open his mouth before Mabel went on her tip toes, kissing him on the cheek, and was running off yelling thanks.

And there was no way he could possibly say no to that.

Which was how Bill ended up sitting in the grass, staring into the eyes of a pig.

"You know, Shooting Star is quite fond of you," he said as he spread his legs in front of him, leaning his elbows on the grass.

Waddles only turned his head in response, his small eyes focused directly at Bill.

"... It can actually get kind of annoying, when she is focusing so much on you that she pays no attention to anyone else," he continued, his stare at the pig turning into a glare.

Waddle stood up, pushing his shout against the bottom of Bill's shoe.

"... I suppose if you make her happy, though, that is the only important thing."

Bill turned away from the pig, looking down the hill he was sitting on at the town below. His focus was only brought back to his physical location when he realized that Waddles had slowly walked onto his lap, curled up there, and promptly fallen asleep.

That night, when the sun was about to set over Gravity Falls, Mabel, after searching for the two, eventually found them on the same hill, Bill staring nearly unblinkingly at the pig.

"Awww, how long have you two been like that?" she cooed, picking her pet off of Bill's lap.

"... Far longer than I wished to be," he responded as he stood, brushing himself off.

"It was so cute, though!" she exclaimed, grasping one of Bill's hands with her own that was not supporting Waddles.

"If you think so, Shooting Star."

"Pffft, what's cuter than a sleeping pig on your lap?" she asked seriously, an eyebrow raised.

"How about a sleeping star next to you?" he responded smugly, causing Mabel to blush and push him lightly.

"Stop it!" she said, looking down with her still glowing cheeks and a small smile. After a moment, though, she looked back up and spoke again.

"Seriously, though, thanks Bill. It really means a lot to me that you took care of this little mister today." Before Bill had a chance to respond, she quickly kissed him, effectively silencing anything he had been planning on saying.

"I promise, tomorrow we can spend the day together, no distractions," she said solemnly before dashing back in the direction of the Mystery Shack.

"I'm counting on it, my little Shooting Star," he eventually called out, happiness evident in his voice.