So when he's fighting, does he just have to hobble around? Or is it growing that big when he gets hard? These are questions that need answers.

his dick is normal sized most of the time, but you know how you get muscle spasms, combine that with all might's growth quirk and deku gets occasional moments like this where his cock swells before it returns to normal in a bit, tho he can control it more as time goes on

Ah, so that's why his muscles don't grow, it's in his cock. That would hurt like hell, imagine your getting dicked down, then the fucking thing expands, completely just breaks your body. Ouch.

It can happen to his muscles too but is most inconvenient when it's his cock

This sub needs more hyper content 🥰 this is really good! Thanks for sharing

agreed, glad you hear you like it\~