What's his motive?

[Emmii]

To cut a very story short, I was seeing this guy for about 9 months and I ended it as he started playing mind games. A few days after I dumped him (This is bad of me I did it via text which is what he tends to do) he jumped on to another girl who happen to be his brothers girlfriend's younger sister. Whenever I bumped into him I would be polite and say hi to him but he would make sexual innuendo's to me and reminisce on the past which I just shrugged off and ignored. Enough is enough I put my foot down and told him that he should stop doing these things now he has a gf. To which he said I'll stop talking to you from now on. I was fine with this. Regretting what he said he kept passing msgs thru to my friends which I ignored and trying to get eye contact. We haven't spoken for 9 months. The last few weeks he keeps trying to get eye contact with me. But I've ignored it. He looks miserable and he doesn't have that twinkle in his eyes. He told everyone that his gf is the one and his smitten with her. Until last week I was doing some things and he kept asking if I was using these things and I said no. When no one around he came over to me and said can I speak to you. I said yes. He said he couldn't come into the room and not speak to me. I just shrugged my shoulders at him and he carried on saying it's not right and didn't say a word. He asked me if we were ok? I said yes and had no hard feelings. I told him I never had. And he kept saying we ok? He wanted to shake on it and just gave him a no look. He just walked off. Then throughout the day he kept trying to get eye contact with me but I ignored him. The next day he came over to get my attention but as soon I saw him walking towards the room I pretended to be on the phone and he just stood looking at me for a few minutes and left.

What I find weird is that he has a gf that fell pregnant Four months into the relationship. If you're happy at home you wouldn't miss an ex but maybe it's my way of thinking. I think it's odd. What's he after? Why use reserve psychology on me? Why did his face light up since I spoke to him? Is he genuine about friendship or does he have a hidden agenda? He's going out of his way to get my attention just for friendship. Please can I get some advice. Very confused.