If they don't shower and smelling like sweaty armpits then I wouldn't be dating that person. I'd only date someone if he showers and uses deodorant. certain body odors turn me off.

If you're not attracted to them in general then yeah obviously break it off. But if you like them (which I guess you do since in this hypothetical situation you're already dating them), then surely their smell is not a turn-off? If they get sweaty and smelly sometimes, they just have to shower and then it's fine. But if their natural smell turns you off, if they are greasy and dirty and smell like rotten onions all the time, then why did you go out with them in the first place?

For me at least it's important that I like how the person smells. It's one of the things that I get attracted to.

If they never showered, washed their clothes or used deodorant, then yes I could.