I would tell him that the next visit to your home will be different. You will not be listening to his sexually explicit talk, don't want to hear about his partners. Then, tell him he has 3 children, and you would like to hear about all of them equally. My guess would be that two of them have chosen to stay away from him because he is embarrassing, so that is why he doesn't have much to say about him. What do you think? You have to do what makes you comfortable, and just tell him what is acceptable in your home. Good Luck!!