Why won't he talk to me?

I've text him, tried talking to him over FB chat and yet he refuses to reply, I just don't understand what I have done wrong? One minute we are chatting most nights, having a laugh and all and the next he seems to have turned cold on me? I want to ask him, but I don't want to p*ss him off, any suggestions as to what could be wrong?
Why won't he talk to me?
Post Opinion