Why would my ex contact me and then stopped talking again?

[Maya N]

he was in love with me, i broke his heart, then realized i had feelings for him. too late, he started hooking up with some girl in his dorms. this was about 5 months ago they started going out just cause she f*cked him i guess. anyways i didn't want to stay friends with him even though he wanted to. we stopped talking and then he texted me on new years, we talked for a day and he didn't talk to me for 3 months and randomly texted me and added me on fb and myspace! i had deleted him from both a few months ago. when he texted me he wanted to hang out even tho he still has his gf and i now have a new bf.(we never had a sexual rela so it wasn't a booty call) he texted me for a few days then blew me off when we were supposed to hang out and hasn't talked to me since and it's been over a week. i'm just curious as to why he contacted me? just wondering why he wanted to hang out with me? like all of the sudden