Why does he call me if he's really 'not that into' me?

I'm guessing he wants you around as a backup.

Walk walk walk walk walk away. He's just using you for sex.

He calls you when the other friend with benefits are not available. If he is not that into you, why bother? You signed up for it (FWB) and you can revoke that contract RIGHT NOW. And honestly, the best person to ask this question, is to ask him directly.

Time to wake up! Did you say he has plenty of friend with benefits? he could get a STD and past it on to you. Remember, even if he is using condoms, he could get HPV and past it to you via kissing. If he performs oral sex on one of his friends with benefits and vise versa (if she doing oral on him with no condom) they will all get HPV. STAY away from him and find a person who is worthy of your love. (and someone who does not use you as baby sitter for his kid). Look at you in the mirror and think about your qualities and his. However, if you feel you are not worthy of a good man, then keep on going with his booty calls. Only you have the power to brake the cycle and fall in love again with the right person.

I had this similar experience. The guy I was with only called on his terms. If I got to close he would find a way to break it off, but he would always call back. Sex may be a reason, but it is also because he misses you. He may not want you too get over him. Ask him and do yourself a favor. Do not call, see, or text him for 2 months and then see how you are feeling. This will drive him nuts.

Just ignore him...This guys does not deserve your love! Plus, he does not care about your feelings. Guys seem to have a switch that they can turn on and off. SO don't let him turn that switch as he pleases.

Some guys always want to keep a girl around as their "comfort girl". She'll always be there when he wants something from her.

Girl, you deserve better than this. I have been there, it won't change and you'll only get hurt.
I know you don't want to hear that, but based on what you wrote here it seems to me that he has too many issues to ever treat you right.
I know how hard it is to let go (i was in this kind of relationship with ons and offs for 6 years!) but I am so happy that I finally realised it/he will never change and stepped out.
Best of luck!
Remember, he has no right to treat you this way, you deserve better, and you will get better as soon as you let go of him.

He is toying with you. Have you tried to find a guy and move on? I think that would be the best. He sounds like a winner that is leading you on whenever he wants something. Sorry to sound so mean and cold. He is not a nice friend first off. Stop contacting him and move on.