Interesting Story - need advice

So this is my first post to the reddit community and I'm hoping you guys can help me out. I've known I was gay from an early age but I've never come out because I didn't want to deal with the drama. Because I know my family would shun me and some of my friends would certainly be put off by it, I choose to keep it to myself.Lately I've been having a strong desire to come out to at least one of my friends because I'm really just tired of hiding it. I haven't been able to figure out who it should be but then a couple months ago something happened.I was browsing Grindr and got a message from this headless torso profile and decided to respond. We talked a little bit and swapped dick pics and then I ask him for a face pic. When he sends it I am completely astonished. It was my best friend (who by all appearances is straight as an arrow, he rags on gays quite a bit too). I stared at my screen in disbelief and did nothing. He still doesn't know that it was me he was talking to. He disappeared for a while and showed up again about a month ago. We messaged a few times and then he went silent. Hasn't been back on the app since.The predicament I find myself in is that I am attracted to him, and if some kind of sexual relationship were possible between us I'd be so down for it haha, but I'm deathly afraid of making things awkward between us by bringing it up. I know I shouldn't be since I found him on Grindr but the thing is, I kinda feel like he was just on there to bust a quick nut. Since I haven't seen him back on Grindr in a while I'm suspecting that he is at most heteroflexible.So my questions are: Should I come out to him? If so, how should I do it? Should I talk about seeing him on Grindr? Knowing that I'd welcome a sexual relationship but don't want to damage the friendship, how would you proceed?A couple of details - we're both in our early twenties, both very straight acting, and very good friends. We spend a lot of time together (hours a day) and used to live together.