Oh my- this person sounds horrible. Maybe, if you don't want to annoy them, be a pest and be overly nice to him. Or better yet, pretend to be his secret admirer, send him chocolates, pictures of him with hearts until he's annoyed so much he explodes. Also, you could try figuring out how he got this info in the first place too. Punish both of them then and give them karma. Someone in that chat you are in must've told someone.
