Would it be bad to remind my childhood friend this issue?

When i was little i was friends with this boy and he an i used to play all the time and i remember thinking he was cute since kindergarten.One day both of us 5 years old went to the bathroom and i didn't remember why but we were sharing the same toilet to pee he the closed the door and we did stuff, stuff that for adults would not be considered or near it, but for 2 lil kids wasn't right. We did it several times until the security guy caught us but he just saw us sharing the same toilet and he was all"wth are you doing?" and we both were like "idk! This dude here is crazy and starting peeing next to me without asking blah blah blah" and we decided to never do anything again. I moved that year and never saw him again. All my child hood i made myself believe it never happened and that it was all a dream, but it didn't work, i remember it clearly. The other day i looked for him in facebook and there he was with a girlfriend..and i was surprised cus i tought that just like me he would grow to be gay 19 year old. I didn't ask him for a friend request or talked to him.. But i kinda want to .. But i dont want to cause trouble to his relationship with his girl, neither do i want to remind this to him if its gonna make him sad. But i just want him to tell me it wasn't a dream and that it actually happened... Please dont make fun of me this smthng i wish never had happen