Dear cranberry:
My suggestion is that if he makes it possible for you, get to know him, learn more about who he is while not having sex with him.
First, get to know a man, learn who he is, then consider a sexual exchange with the man.
You already learned something about him, that he flakes out of plans he makes. This is valuable information. Because even if you do get him interested in a committed relationship with him, he will be inclined to flake out, to not keep his word. So maybe better not aim at a relationship with him at all…?
anita