Date with the ex?

Ok so like I said a few days ago my ex and I were gonna meet up today. Well we did ended up going to our usual place. Then since he just bought a stick he showed me how to drive it. Because of the direction I went we went to see a movie while there we started fooling around till a guy came in the theater. During the movie I noticed he was texting someone and hiding the screen. And after the movie he was saying maybe we shouldn't have sex and that it may complicate things which I agree. But it made me suspicious so I asked him who he was texting he ended up telling me that it was a girl that he met last night. He said he doubts that anything is going to happen between them but we also don't know what is going on between us which is why he pulled back. THAT THAT RIGHT THERE is what is killing me. I acted like it didn't hurt but the second he drove off I started straight ugly crying. I don't know what to do. I want to be with him. The him that he was when we met up before she started texting him. The one that he was before I started pushing away a few months ago. I'm confused and hurt.