My boyfriend bought a butt plug. Is he gay?

Me and my boyfriend are 16. We've had sex a couple of times but we never went over kinks or anything because that's probably considered a bit too much for our ages. My boyfriend just texted me like 12 minutes saying guess what. I said what and he said I bought a butt plug and I really like it. I said what the hell are you doing with one of those and he was like for my prostate obviously. I said why are you telling me this and he was like because we agreed to open communication when we first started dating, sorry i made you uncomfortable" and i just left him on read. I don't have a problem if he's bisexual or something but what if hes gay?