"I know I'm not going to stop her seeing you. But don't you dare stick anything of yours inside my daughter!"
It would have been funny even at the time, that coming from his college roommate's father. But Alph had discovered something - true to it's portrayal in every sitcom ever, the police chief father nursing a shotgun while making that sort of threat was genuinely scary. So Alph had agreed, rather meekly, and in his time rooming with Sayu hadn't once broken that promise.
Technically.
Bit by bit, they had discovered that not being able to 'have sex' didn't stop them being sexually active. Hell, the fact they were happily limiting themselves to safer options probably made them more responsible than most forbidden couples. True, the entire thing was built on a tenuous line of loophole abuse, but Alph didn't particularly mind. After all, the benefits were more than worth the risk.