Back on the 21st my best friend stopped talking to me entirely. We've been friends for a very long time and have always been pretty much inseperable. No topic has ever been off limits and we've always been open and honest with one another about anything and everything. I'm single recently out of a relationship which imploded - ie. she went back to her ex. He's divorced, fighting for his kids, and is in the middle of a relationship with his girlfriend that exploded. Since he's not speaking to me I have no idea what happened however I did notice something peculiar the weekend before. While doing some Christmas shopping we both got talking about our past relationships. During the course of that conversation we both came to the revalation that he slept with my fiance at the time - like 15 years ago. We didn't up getting married because my former best friend also slept with her at the church on our wedding day. My new best friend and I didn't even know each other existed back then and I had no knowledge that my fianace knew him either. We both literally stopped dead in our tracks and things got VERY ackward. I told him upfront immediately that I wasn't upset with him or anything because that's ancient history and I didn't even know him back then. We went to dinner, talked some more and I thought everything was fine. Then Wednesday I get this wierd text that just says 'leave me alone' out of the blue. A mutual friend has tried to pry out of him what is going on and he's been deliberately lying to her trying to get her upset with me too which she immediately saw through. I'm clueless to exactly wtf is going on. Is it possible that this knowledge is the cause? If so, how do I handle it. I value his friendship and his continued silence is killing me. I've never seen anything like this.