Finding a manga(??)

ok guys
I remember seeing this on a tiktok, I'm not completely sure what it's about It wasn't colored; all I remember was this dude with black hair and this other boy with lighter hair.
They were both in a gym equipment room(?) where the black-haired boy was against some things and the other boy was asking him if he wanted to see smth cool(?) he then started making this hole that went through his body, I think he also asked or wanted the black-haired boy to touch the gap in his body or smth
I think they were together?? I literally forget and I feel like my description is too vague
if you guys know what I'm talking about then pls help me find the nam ╥﹏╥