My son is a misogynist — please help

My son, 16, had some friends over on Saturday night and they were in the living room, I was in the kitchen. The door was open. We’ve lived in this house our whole life and he knew I could hear the conversation.He and his friends were having a conversation and to summarize a friend complained that he had been on a date with a girl, he payed for her food, and they went somewhere in his car, and they started to have sex but she changed her mind halfway through.I heard what at first I thought was a friend my son wouldn’t be seeing anymore, say “nah, you shouldn’t have stopped. By the time you’re in her the p*ssy pass has expired.” And I turned to see who it was (the tv was on and also it just never would have occurred to me this were my son) but it was him who’d said it.He saw me standing in the doorframe but he continued, saying (I’m going to paraphrase because I’m too disgusted to recount it all) “it’s not your fault she regrets giving it up or only wanted to go until she was finished. She went with you, that’s consent.”To my relief, at least, his friends were obviously super uncomfortable with his remarks. One said “that’s really not how it works” and the one who had the date said “I mean I was mad and I’m still mad but if I hadn’t stopped that would’ve been rape dude.” And my son casually brushed it off like “nah, it wouldn’t have been.” And the conversation died down and his friends left within half an hour after this.So I kind of organized my thoughts and I read some articles online and I searched the past for how I went so horribly wrong (I’m amicably divorced from his mother and have partial custody, on weekends) and I called her to let her know what I heard. She was stunned.Yesterday I sat him down and basically said “I overheard you talking with your friends last night. I know there’s a lot of pressure at this age to impress your friends but that was not the way to go about it. Do you believe any of those things you were saying?” And he was totally unfazed and said “yah, of course.”I was unprepared for that. I was really clinging to the belief that he was just trying to seem cool. So I said I was disgusted to hear him speaking that way when I thought it was just macho bullshit but to know he actually espoused those beliefs left me speechless and I needed a minute.Whether it was 30 seconds or 5 minutes I don’t know but finally I said “what if someone talked about your mother that way or treated her that way?” And he said, again paraphrasing, “She wouldn’t do something so slutty.”I was out of things to say at that point and just kept repeating the same things I’d been telling him since he was 12, that he needs to respect women and that consent is not optional.He went back to his mom’s house that night but she has no idea what to do either. She can’t believe it. Neither of us are like, on the front lines of feminism or anything, but we have always had frank and open discussions about proper sexual conduct and general social “You don’t mistreat someone because of their race/gender/creed/etc human is human”I may be rambling at this point or ranting I don’t know but my ex is at a loss and so am I.Any advice welcome. via /r/Parenting https://ift.tt/2oLupbw