Should I end our fling or keep it going since there was never any commitment involved?

I'm moving to the other side of the country for college in the fall so a relationship is obviously not in the cards. But anyways I've had a fling with this guy since prom in May. Meanwhile I've been hanging out, dating, and talking to other guys but I've kept it low profile. Yesterday this same guy was tagged in pictures where he was on the ferris wheel with his arm around a very unattractive girl (troll!!). I am offended because not does she look like my left toe, he had the nerve to hang out with me that same night and try to get some action... (I have only made out with him a total of 4 times since February). Now I just feel like he has no standards since he would put me in the same league as her even though his friends have all given him crap saying that I am the best he will ever get. Also, he told me a few nights earlier that he really liked me, and then I see this. Should I end the fling and just be friends? It's not like we have a commitment but like I said, I'm offended.