My feedback will not beat 'round the bush; a bit of fair warning before I begin. To note: I understand this to be your first time; while not terrible it has errors that I think you need to stomp out before they become habitual. Crack pairings are fun and Mirajaine is a favorite of mine amongst the whimsical Fairy Tail wizards.

There's a lack of characterization for Natsu; he wouldn't be embarrassed as the boy casually strolled into the woman's bathroom stark naked without a care in the world before. Natsu and sex has always been up in the air because I swear Hiro isn't sure if he wants Natsu to be a complete idiot or have some sense of awareness outside fighting and friends. Had Mirajaine approached him like this, she would have been met with his boyish innocence and her toying with him would have been far sexier, serving to shatter said innocence. Dialogue felt weak, and when they were having sex it felt... cringy. I would delegate dialogue to its own paragraph but there isn't much I have to say on the matter that isn't summed up there.

Down to the meat and potatoes the writing itself: your diction is prosaic. You try and describe every little thing that's taking place and it reads really choppy-like. You don't have to describe every motion - the lack of vocabulary variety doesn't help your case either - because we can imagine what's going on without the needless padding. It reads as if you want to have it wordy rather than steady, concise paragraphs depicting a sexy endeavor.

The idea's hot; Mira taking Natsu for himself, his body hers to command for the night, I like it - but when it's not executed properly it's kinda eye-twitching to read. You had a strong start with Mira dicking him around, get a few good moans out of him (noise you don't have to describe in dialogue, just "she moaned" is fine) but when it gets to the sex, the real meat and reason for the story, and it isn't that good, the whole thing falls apart and the ending makes it that much worse.

Try again, read other people who've written smut themselves or have done so for long enough of a time. The story isn't terrible but it ain't the greatest with stagnant dialogue, needless exposition, and a disappointingly repetitive sex scene. If you want me to clarify or point out some things specifically feel free to PM me.

*whistle* I’ll tell you what, that was one steamy story. For a first time at smut (if I recall correctly), you did a pretty good job. You had a good amount of details that was sufficient enough to push the scene. I can say that because I was certainly hot and bothered after reading that one. Keep up the good work!

Really nice for a first try. The only things that could have made it better would have been if there was a little more of a show with the bath peep before being found out, if Natsu used the cuffs and crop on Mira, and maybe if their little encounter got to continue.

Still really great. Looking forward to more.

What kind of retarded ending was that?

It was really well made smut with nice build up in just a few paragraphs. Though that final twist seemed really strange. Either way, hope you make more stuff.