If he is not done with his marriage that would lead someone to assume that your relationship is not what it is for you. We can't decide someone's motives for certain but actions are an indicator of what we really feel. Another indicator is that he is not done with his marriage as you are. This says that his heart probably lies with his wife and you serve another purpose. I would not knowing this waste anymore of your time. If he planned to leave that would be something else. You don't want this to mean more to you than him. You should want an equal relationship with mutual commitment. I would find out what purpose this serves for him. If he truly only wants a sexual relationship then you can make a decision based on that. If he is committed to his wife then you participate with an open mind. It is possible when both are married that this is simply sexual in nature. It is up to you whether an unequal commitment is worth your time. I would look at his behavior and his words combined to see if these equal a purely sexual intention.