Is it bad for you to take showers at night?

So I'm a dancer, and I use all sort of hair junk in my hair, and I get sweaty and all that fun stuff, so I take showers betweenn 9:00 and 1:00 LOL and my brother is all like 'Taking showers at night is bad for you.' Now his girlfriend is miss goodie two shoes, everyone will take care of me, so I don't have to get a job or go to school.. so I usually tell him his girlfriend has indoctrinated him. Anyways, is what he says true? Or is he just being a power freak?