How do I start the conversation?

So, my best friend and I showered together. We were on vacation and we both had to shower and we were about to leave for the airport and we just showered together. We faced away from one another and thankfully the hotel shower was pretty roomy so we could shuffle around each other, but he hasn’t looked me in the eye since.

What do I say to him? I don’t even know where to start. Like, I’m attracted to him, yes, but pretty much everyone he meets is attracted to him. Do I just let it go and hope he does the same?