I thought he had my back!!!

We've known each other for some months now. We started of being friends then he became someone I started to look up because he was much older, we had a lot in common, and he seemed to have a good head on his shoulders. Up until 3months ago, we were friends until things started getting sexual between us. Neither of us wanted a relationship so we agreed it was just going to be sex and we wouldn't let that affect our friendship. Nothing changed between us; we were friends when we needed to be, we were co-workers during the day, and we made love when the time called for it. About 3wks ago, I noticed he wasn't calling or texting me as he normally did. I didn't make a big deal of it. On the 17th if June, we had a work function which he told me he wasn't going to attend but somehow, he was there. He barely had a conversation with me the entire night. I took note and I gave him his space. Throughout the days following that event, he didn't call me, no text, and he wouldn't even talk to me at work. At this point, I knew something was up so I texted him and he's like "I've hearing stuff about you. Shit you say, shit you do..." I asked him to tell me what he's heard about me and he goes it's to long to text it to you so I'll call you when I can; never got a damn call from him. I asked him to come over so we could talk; told me he couldn't make it. He still hasn't made any effort to tell me what he's hearing about about me; Hell, he doesn't even call me anymore. I deserve to know whatever people are saying about me whether it's true or not; I've a couple of people and they swear they haven't heard anything about me. I just feel so betrayed because I've had to defend him so many times to people who didn't approve of him and  not once did I  believe anything anyone said about him but he couldn't do that for me. It's killing me that some crazy lunatics are spreading false information about me and I don't even know what it is.