I think your father's sex life is none of your business. Why would he be interested in your opinion? Do you really think what you say will be news to him? I'm sorry if your mother is confiding in you. She really should leave you out of it. This is between them, especially if you are no longer living at home. Trust me, you don't want to hear details, and you don't want to get stuck with either one of them. You have your own life to look after.