What do you do when you meet a woman at a party who makes an offhand comment about her "worthless son"? Nothing, right? Maybe "That's really rude" and walk away

What do you do when you meet a woman at a party who makes an offhand comment about her "worthless son"? Nothing, right? Maybe "That's really rude" and walk away? Certainly no crusade will be mounted. Because: she's simply a bad person[1], and nothing you can say will do anything, you won't change her mind or shame her, and you certainly won't help the son's case, and anyone who knows the woman in question will know she's a jerk already. There's no point. Jerks are jerks. They come in both penis and vagina versions. Many of them are famous. As for the guy who wouldn't talk to you, here's what you do: "Excuse me. I'm over here. I run the business." Then smile. I once did this to a guy who was trying to sell my boyfriend a car… when I was the one shopping. ("Excuse me, I'm the one with the money.") It solves the problem immediately. It causes temporary embarrassment for the lunkhead, he'll stop, and believe me he'll "get it" because he will stop trying to get the handy local man to explain why you/he are there, and you can all move on instead of silently steaming for ages. It also works when somebody is at a dinner and saying "Women do this" -- you can simply say "I don't." And if that person is a prominent woman tech blogger, and you are me, then she'll shun you for the rest of the event, which works out just fine! Like I said -- jerks come in all genital varieties. [1] or maybe this angry mother isn't a jerk, maybe she's "just having a bad day," and "made a mistake," and makes a comment to a bunch of people at a party instead of photographing her son asleep during a test and using her position of power on Twitter to get him kicked out of his university… luckily for her, she's a woman, so she has the option of making a mistake in airing out family dirty laundry and being forgiven(?).