Showering together? Is it okay?

I've showered with my best friend or whatever you want to call him. Friends with benefits I guess. We didn't have sex, but he wants to while we're in the shower together. We're 4 years apart, but we've been friends since we were very tiny peoples. Is it okay to shower with him? Would it be okay for shower sex? It's not like we haven't fucked before, though. I've heard it's amazing but I just don't know cuz we haven't tried it. Just a tiny bit of advice or help? Maybe? Please?