Dorm Mates (Mate Trilogy #1)
Lenore Moreau

When omega Ethan Rain decided to touch himself the first night in his dorm, he thought he was discrete enough to hide it from his roommate. But Cameron, an alpha attending college on a football scholarship, isn't so easily fooled. The alpha wants to makes sure Ethan doesn't put him in that sort of position again, so he takes matters into his own hands. Can Ethan handle giving up control?
This MM omegaverse short has mentions of mpreg.