Your **** buddy does not have good character. He uses you when his girlfriend relapses and then he throws you away when she wants to be a girlfriend/mother again. He is not putting you first; never did, never will. Your just convienent for him when he has the time. He wipes his feet on you. Don't be a doormat to anyone girl. Cut him off.
He is using you. Cut him loose and move on. Find someone who is not encumbered. Life is too short to burn daylight.
He had you and his kid while she was a mess. He could easily have gotten custody, married you and given her visitation when she got her act together. He chose not to do that. My answer to your question is YES, he is playing you for a fool. He is not going to leave her for you. Move on. Why do you want to continue to be second best? Look within, not at him.
So he calls you when it is convenient for him ? And then when this woman who is the mother of his children is in trouble, he calls you and has you step in ? That is WRONG and I don't think it is wise for the other woman to be around these kids !
In my opinion, he is taking advantage of you. I guess the question to ask yourself now is: are you going to let him continue treating you like this or find a man who will treat you with respect ?
One thing that comes to my mind is that if you start a relationship that is just casual sex (as in this case.... the "booty call"), then what are the chances of you having a real relationship and that person ever respecting you ? I don't think they are too high.
sticky situation. my suggestion is to let them be. you were in a relationship that involved cheating. im sure you love him and the children, but they are her children. if he chooses to be with her out of love, or guilt, it must be hard for you to stand by and watch this. dont you feel you deserve better than to wait around for him? i think you do. if it were me id tell him that you cant wait around for him to become available. you will continue your life, and if or when he is single then you can see what happens then. if you truely care about those kids, you would stop the affair, remember it hurts the children as well. best of luck to you!
He seems to be feeling like he is "stuck" with this woman, having two kids and her not being able to stay "clean". It is admirable for you to step in and take care of his little ones while she is going through her moments. If she ever did find out she would more than likely return to her old ways, as she seems to be very unstable.
If I was in your situation, I would try my best to separate from him until he works out these issues on his own.
Now, lets say that he did leave her and was with you for good, what makes you think that he wouldn't be doing this to you? He is involved in an relationship with another woman while with you already, what makes you think that it wouldn't happen to you? You say he cares for you, as I am sure he does, but do you think that he would change?