What's up with my ex?

at the end of last month my ex and i broke up. right when we broke up i deleted my myspace because the only reason i had it was because of him and i prefer facebook. right when i deleted it he started immediately getting on facebook more. this was bizarre as when we were together he would tell me how much he disliked myspace. our break up was "eh" and didn't go over too well which sucked because we had been friends for four years before we dated. though we went thru the exact same charade with an intimate relationship a year ago. it happened all over again. because of our break up and his attitude towards we i decided not to attend his grad party. he wasn't happy about this when i told him but all the sudden all of his status on facebook were pertaining to this party and how great it was so on and so forth. this was weird too because this happened after a month of him not being on facebook so very random. we talked not too long ago and he seems mad or a little odd with me which is weird because he was the one who kept stressing how much he wanted to remain friends. i commented on how ofter he gets on facebook and it got to the point where he told he had "another reason" he got on facebook so much. so of course as an idiot i asked and he told me it was because of a co worker he likes. he then went on to ask ME for advice on getting her # and told me all the places he wanted to take her on a date, all these places being places we discussed going had we still been an item. this just made me mad because it was kind of ish i thought and he kept saying how he was over me right when we broke up so on and so forth. alot of my friends and fam think this kid was trying to make me jealous in some childish way and i really don't know. this is the second time this has happened with us and he always comes running back to me. the last time he liked this same girl then me then again he likes this same girl. we will be attedning college together and will have the same cles. i am ten times more outgoing than he is and he is rather dull with very few close friends, i was his closest. he is a mama's boy, obese, and rarely leaves his house. i am the exact opposite. he also is kind of lazy and lacks ambition and confidence though he is a nice kid really but idk if he just got big headed after dating me or what. we no longer talk, i said i might talk to him in college and i deleted him as a facebook friend because i couldn't be leave he set it up so he could tell me about his new crush. idk what to think but does anyone else think his actions were a way of attempting to make me jealous? he isn't one to approach girls, he is actually intimidated by us and has had two gfs in his lifetime. i don't even know if it is worth being friends with him again though we were so tight. any input?