a grown ass man doing it with a young adult I feel sick

So a grown adult with young adult?. Math aint mathing homie

Idk how to describe it as English isn't my native, but it's just weird
Like isn't a young adult a dude who just turned 18?

I understand that he used to be a child when they met but I'm sure (not really) he's adult now? I guess you meant teenage but that would mean he's under 18