My problem . . . well, one of the many

I've been trying to figure out if my story has enough conflict in it and I'm not sure it does. My characters want to be together and there isn't anything really keeping them apart except for themselves. She's not very trusting with a long history of making extremely bad choices in men and he's made a promise to keep up the pretends with his soon to be cheating ex-wife for the sake of the woman that they both love (her mother) who is dying from cancer.

Initially I thought that this would be enough of a "problem" for them but I don't think it is. The story has stopped dead in it's tracks. I'm not giving up though, I will think of something. If nothing else maybe my characters can help me to create a deeper conflict. Lord knows that they have helped me stray completely away from my initial timeline.