I think you need to stop with the assumptions and just get on it . The more you sit there and let it happen the worse its going to get . you already know what's happening . He clearly is lying . you deserve better don't let no man cheat on you . sit down and have a serious talk with him. Tell him how you feel and everything you basically just said of what you wrote in this paragraph and be very serious don't give in to him and let him off easy. Be on his ***. And it would be better to not have a man like that in your life then even for the kids . I'd rather be a single mom then have kids and the father is out cheating doesn't look good. Let him know you will leave you need to give him a taste of his own medicine and give him a reason to be scared . If you really want him and the relationship don't sit there and let it happen . do something about it. Get rid of the woman let her know he is taken and he is not single . Be very clear to your boyfriend . This is not right at all and no one deserves to go threw this . You shouldn't have to either . sit down and person and have a long good serious talk tell him you know the truth and its quite obvious. If nothing changes after leave him . Your not worth his time if he wants to cheat and go behind your back !! Don't stay with someone like that !!