best of (boy)friends?

Why is it that relationships usually end on bad terms?I used to consider my ex one of my best friends.I'm not delusional I know we can't still be that close,but to at least be courteous would be nice.A week after we broke up he knew I was going to be at a party so he brought a date,this blond,blue-eyed babe.I didn't stay at the party I left almost immediately because I don't think a full week was enough to get over three years of a relationship and seeing him with the future playboy playmate all night would've killed me.I keep on thinking what happened to him,was he this catty when we were together?How did we go from being very much together to practically strangers.There's no forgetting all the nasty things he said about a minute before I broke up with him, and I didn't forget his refusal to apologize.I thought if anyone would be getting revenge it would be me,but that wouldn't feel right.Then every one's saying "good for you Jasmin taking the high road" but why do I get credit for doing what I think is right?The getting over someone process has nothing to do with him.God relationships suck,no they do,I wonder if they get easier when we get older,probably not that's why almost every adult I know is divorced(no offense).It's almost enough to make me give up,but then I remember the butterflies in my stomach and the excitement of having a new crush and then I get it, if only there was a way we could know for sure that under the butterflies and excitement there was something real.