He walked back his original comment because he knew you were upset... not because he felt differently. He still wants to bang other women and will do it with or without your permission. You can decide that an open relationship is acceptable, you can wait for him to cheat and then decide how to proceed, or you can end it now before he gets the chance.

But make no mistake: he will try to have sex outside the relationship whether you're on board with that or not. Whatever decision you make should be made with that knowledge at the forefront of your thoughts.