Why did my bed buddy throw random insults at me?

I have only recently started seeing this guy purely as a bed buddy. He said that I should not develop anything more for him and I told him that I want something totally uncomplicated. He is actually kind of a narcissist and egotistical but I was just having fun with him so I didn't care. We've seen each other 4 times and the last time he started throwing random insults at me...criticizing me and even making pokes at my intelligence..like just because I have a masters degree doesn't mean I am smart...or stupid things like my laptop is too old...i contradict myself too much. What is up with that? We are just bed buddies and he has no right to say things to me. we shouldn't even be talking for that matter. I don't understand this behavior. I was happy the way things were and now I have to stop seeing him which is really disappointing. I told him he was obnoxious and egotistical. Any ideas on why he would act this way and should I ask him why he behaved in such a manner.