@bunbun123 That's so strange, but it might be that he is seeing someone else and as a result he lost interest in you. There is no way a guy will not get aroused when he is around his lady.
Unless you have no teeth it is logical that it would painful. A baby forces the milk out by pushing the aeriola against the roof of its mouth, if there are teeth the nipple will be rubbed against them. And cheating on your wife and children will bring you all problems later. You can never rely on how 3rd parties will behave.