Gay work colleague outing me to everyone else

As a discreet gay guy at work (I am not discreet outside of work) I recently chatted briefly on Grindr with a guy at my workplace. Now, it was just chat, not "chatting up" or anything, but seeing as I don't usually speak to him anyway (it's a large workplace) it could be seen as a bit weird I guess. Anyway, the chat was pretty cordial, and he was surprised that I was gay. He even said things like "youre attractive" etc., although I don't think in a flirty way. However, literally the next day at work, everybody now seems to think I am a gay guy in the closet. All of his closest friends look at me funny (not sure I even care tbh) and someone even made a silly comment today that sort of upset me. I guess I was played for a fool by the gay guy on Grindr and now he is telling everybody, so now I cannot be discreet about my sexuality. This makes me furious tbh, and I am very angry. I want to know what to do next - has he actually broken any generalised rules about revealing my sexuality to other people?