Boyfriend doesn’t shower...

Hey! Tell me if I’m wrong but I’m extremely turned off from my boyfriend right now. I’m a very clean person, I like to take care of myself. Recently my boyfriend hasn’t been taking showers...he works at a car oil change shop and goes to the gym regularly (someone who definitely needs to be taking a shower daily) and he hasn’t in a week 🤢 he thinks it’s funny and honestly I don’t want to have sex with him because I don’t want to risk getting an infection...how do I tell him he needs to take one without sounding bossy?? I’ve brought it up and he’s explained his reasoning (doesn’t make sense) and that’s as far as I’ve gotten. Ugh.

Edit:

For all you asking his “reason” for not showering is he is “experimenting” lol with his scalp...he has a dry, itchy scalp BUT here is where it gets confusing and makes no sense...he still washes his hair under the sink and says he still wears deodorant...if the scalp is the issue I don’t understand why he would keep washing his hair but not his body?? You can go a few days without washing the hair that’s fine I do the same but our bodies need washing more.