Notes:

This chapter is /very/ sexually explicit. You've been warned, carry on.

Chapter Text

Mycroft knew he was going to like being able to eat whatever he wanted whenever he wanted to -of course he did-, but he hadn't anticipated such pleasure in his wildest dreams. His previously tortured stomach never again had to go empty for hours; now it was always full, always satisfied, anything it wanted was immediately provided. The sensation of being constantly full was simply glorious, nothing he had ever felt before compared. The warm feeling in his belly after every meal was so delightful he honestly found it quite addictive; more often than not he stuffed his face silly with treats just to get that feeling again. Mycroft was enjoying himself so much he didn't even have a second thought about it when his uniform started to fit him more snugly; he actually felt quite relieved now that weight was off his mind. He wasn't gaining uncontrollably either; a little bit here, a little bit there… He was definitely softer and rounder, especially in his middle, but just enough to make Greg blush every time his hand brushed over his tummy. Having such a strong effect on him was enough to make Mycroft feel tingly all over too.

That particular afternoon they had gone to the library to study after lunch. Mycroft had been especially generous with himself this time, and his stomach was protruding further than usual. He absently rubbed it as he read his notes, hoping to help digestion, but did not dare to unbutton his painfully tight trousers even though they had chosen a particularly solitary corner and he knew no one would see.

Greg could barely keep his eyes off of him; let alone actually keeping them on his books. He was utterly jealous of Mycroft's hands, massaging his softness, feeling every inch of flesh as they moved through his ample middle; the sight of it was simply mesmerizing. All he wanted to do was to remove Mycroft's shirt and rub that beautiful belly himself.

-I know you think you are being discrete Gregory, but you are practically drooling over my notes.

Greg murmured a 'sorry' but didn't stop staring at all. In fact he leaned closer in and cautiously slid his hand under Mycroft's. Mycroft's little blushing smile was answer enough for him, and he started kneading his fat with enthusiasm. He felt just amazing; soft and warm and just so much fatter than he had been weeks before. Greg slyly unbuttoned his trousers and watched his doughy tummy expand before his eyes. The smile that appeared on Mycroft's face was shy but devious, and Greg just couldn't resist anymore and planted a fervent kiss on his lips. Suddenly, Mycroft's hands were on his tights, rubbing up and down with such skill that as soon as one hand moved closer to cup his balls, Greg thrusted his hips in mild desperation. One of Greg hands kept caressing Mycroft's belly while the other moved towards his crotch and, as he fondled him, he felt the hardness of Mycroft's cock straining against the cloth. Greg was in heaven, and he couldn't keep his mouth shut for much longer, so in heaves he managed to speak.

-Holy crap Mycroft, you feel fantastic.

Mycroft let out a little laugh as he kept thrusting against Greg's warm hand.

-Is that right?

He was barely able to suppress his moans, but he kept talking.

-Tell me more. How does this feel?

He kept one hand on Greg's hardness and moved the other to meet the hand on his middle. He pushed slightly, so that both their hands sank further into his fat.

Greg's breath caught in his throat.

-Good God Mycroft, you are gorgeous, gorgeous.

Mycroft finally reached inside Greg's pants and began stroking avidly. Greg imitated him swiftly, and soon they both were far beyond words. Greg wanted to keep talking, to keep telling Mycroft that he was so fat and so lovely now, but he had been reduced to a wiggling mess, and he had to bite his lip to prevent himself from making any more noises. The library stayed soundless when he came over Mycroft's hand. A few more strokes and Mycroft finished too, his mouth a perfect 'o' for that couple of seconds, but silent as well.

For a minute they stayed there, half naked, planting small kisses on each other and breathing heavily. Then a sneeze from a student at the other end of the room snapped them out of it, and they promptly cleaned themselves as if nothing had happened.

Neither could wipe the smile off their faces for the rest of the day.