I don't get it

Erica
My boyfriend (father of my unborn child) doesn't make time for me anymore. 
We don't live together as of right now, we did, but we separated because of this actually. 
Whenever I ask him to hang out he says maybe, or that he'll think about it, if he's not in the mood to see me then he won't see me. However multiple times his friends called and woke him up then asked to hang out and he just jumps out of bed and meets up with them within half an hour, but he never does that with me. Whenever we actually are together he's talking to his friend constantly and making plans with him for as soon as I'm dropped off, and sometimes he even drops me off home just to go out with this friend to get coffee or something, something small and insignificant, he sees this friend everyday, he works with this friend, and he leaves school everyday at his break to get this friend, but when I ask to go for lunch with him he says no. I just don't get it, he's with this friend almost every waking hour and I'm with him for a few hours maybe twice a week if I'm lucky now, but his friend is still more important than me. Whenever he's out with him and I call he ignores me, he ignores my texts most of the time too, whenever I'm with him though he's always checking his phone. He can do whatever he wants, and I'm not aloud to have a problem with it, but I can't do anything! He does so many things throughout the day that he knows I'm uncomfortable with, but whenever I say something about it he gets mad and says he can never catch a break, even though he's the one doing these things! (Most recently he was talking about sleeping with another girl to his friend, and I asked him not to do things like that because I think it's disrespectful towards me) 
I just don't get it, why is he doing this to me? Why is he disrespecting me, why is he pushing me to the side, why do we have so many double standards, and why does he drop everything for his friend, but won't ever make an effort to see me or make any effort to make me happy!
Edit, by double standard I mean every time I go out he thinks I'm cheating on him and I have to tell him who I was with where we were and what we were doing, or whenever I don't answer his very rare call he thinks I'm with another guy. Even though I haven't hung out with a guy in about a year unless it was his friend and I was with him. However he can go out whenever he wants with no explanation, no telling me what he's doing, no nothing. He has 4 girls at school that he drives around all the time now, this has never happened before, and I'm not aloud to get upset over it or he'll get mad and refuse to see me for even longer, I can't ask questions because he doesn't think he needs to answer to me. Which is true I guess, but all I normally do is ask what they did or where they went. 
I'm always on his time and I hate it, he only talks to me when he has free time, he never makes time to talk to me or see me. If he has a free day and I ask to see him on that day he'll say he'll think about it, but then goes out with his friend and not me. I hate this! I don't even know where all this came from!!