Guy's Behavior

Why does my ex boyfriend keep saying "Hi" to me in the halls?

We were talking for a while but out of no where he starts talking to a new girl and pushs me to the side as if we had nothing going on together. This isn't the first time he has done this to me but each time I kept forgiving him becuae I truly liked him. Now that he is in a relationship with this other female he still says hi to me even though we have had disagreements in the pass but he would only say it if he is not with his girlfriend and/or if Im not with my friends cause my friends really hate him and cuss him out whenever he speaks to me (they're very protective). does he still have feelings for me? If so why does he keep dating new people? He has said plenty time that he wanted to wait until we graduated from school so that we could actually be in a relationship because he would constantly say that he didn't want to be in a reationship in highschool cause he didn't want anyone in his business but then he goes behind my back and starts relationships with other girls... this time im not taking him back because I really want to move on but I just wanted to know a guys point of view on my situation
Why does my ex boyfriend keep saying "Hi" to me in the halls?
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