clarification about ex friends

in my last post i wrote about a prom experience with an ex-friend.
then mel commented that i wasn't very nice to my ex-friends.
this could use some clarification.
the person in question isn't an ex-friend b/c we have fallen out of touch or b/c we just stopped hanging out. he actively decided to become a royal a$$hole and went from being one of my best friends to someone i don't even know any more. i don't know the cause for the sudden change of heart, and i confronted him several times and he didn't have the balls to explain what his problems with me were (or his problems with eric). one day he just became one of the biggest pricks i know.
maybe this explains things.