Just make him uncomfortable and realize he smells gross. Like the next time your in class just say to a friend " what the hell is that smell?" and maybe he'll get the memo.
I totally had a similiar situation last year with this dude that I have known for freaking ever. Except no one liked him. Whenever we were in Chemistry class and were burning things we could still smell him.
If he's straight, just buy him some random spray or something, and tell him more girls will have sex with him if he uses it.
Well, something along those lines, but doing something like that, you can hopefully get him wearing de-odorant or whatever without actually having to tell him he smells.
There is this dude in my class.... omfg. It's horrible. I mean Goddamn. Wow.
Nobody can break it down to him, mostly because he's hot and cute
How do you handle with these kind of things without hurting their feelings ?
A friend of mine told him once but the dude laughed and was like "that's impossible"
If you don't want to risk that **** then don't tell him and just embrace DAT scent because no one else would probably do him.