Friend with benefits

Long story short I was dating/seeing/talking to a few guys over the past few months, no commitment. One of them knew I was seeing other people, well last night we had a huge fight and I don’t even know why he was so upset. I asked him for a picture over Snap, he says you first, I told him jokingly..no fair. He goes “life isn’t fair when you already gotta man”. I asked him what he meant by that and he wouldn’t respond. Then started calling me easy and that I was looking like a fool. Honestly I’ve only seen him 3 times and we only slept together once, why would he go to such lengths to be horrible to me? I don’t even know where that attitude came from. I’m still reeling from it…he was trying to still talk me into coming over and sleep with him until I told him I erased him on fb, then the insults really started flying. The end of the convo he was saying how he had never wished anything from me and that he hoped I knew that when I was over and if I didn’t he would gladly remind me. Prior to this he was saying he liked me, but wouldn’t stand for my “attitude”. (My attitude was me saying he was an ass@:;$ for calling me names, etc.) Anyways not looking for advice, just venting because I’m still upset about what happened. :/