What? Absolutely not. Normal people bathe when they get home, whether they're gonna have sex or not. You get dirty on the street, there's bacteria etc. Naturally most people will bathe before having sex, the only exception is morning sex when you're both on bed waking up and horny
Aside of morning sex, i always bathe beforehand, as well as everyone that i had sex with. I don't know if it's a cultural thing where you live, but saying people don't bathe before fucking is wild. And how would it kill the mood? You can wait for a shower before mounting someone? C'mon dude