My friend didn't invite me somewhere, should I be mad

This is actually the second time he has done this. I am upset, and I don't really know how to handle it. Basically I asked if he wanted to go see a movie on Friday. He then has to admit that he made plans to go with a group of mutual friends a few days later, and tells me "I should go." He never invited me, and if I hadn't invited him and caught him I would have never known he went with the other group. He's done this twice. Also, he's just been avoiding me in general lately. The last few times I've invited him anywhere he either doesn't respond to my text or says he'll probably go, and then never shows up. Do I say something to him, do I let the friendship continue to just fizzle out?
Updates
+1 y
Thanks for your advice everyone. I've realized for some time that this friendship was fading out. However, I have very few friends, he is one and unfortunately the others usually don't act much better. I guess I'm afraid to just end it because I can see myself ending up friendless very quickly. A bad friend is better than no friend maybe? We're in a band together that has really gone downhill, however I can't even leave the band because that is my social life.
My friend didn't invite me somewhere, should I be mad
Post Opinion