Can he cheat if our sex life is way more than healhy?

[Hey]

Like if me and my boyfriend have sex like almost everyday (sometimes more) he cant really cheat cause wouldn't it be kinda hard to get the dang thing up!!! Especially if both partners are satisfied. Juss wondering. I'm not doubting that he's faithful or anything I'm really just wonderin since I don't know much about how it works down there atleast not for them. I'm juss a curious person I guess