The problem is that this dialogue option sounds more like a trap especially for non-native English speakers, and even for English speakers the option comes off as a joke because of the "hot mom" part at the end. And for those who are roleplaying as the dominant, aggressively flirty, NTR kind of guy, you can actually get away with choosing these kinds of dialogue options for most of the game especially towards Anna (granted, she's the only one with the romance/slut system). It's only here with Samantha that it actually doesn't work, which is jarring imo. These are some possible solutions: Either a) remove the "hot mom" part so it's simply, "Your son is a fucking idiot," which makes it painfully obvious that the response is meant to be an insult and not a joke, or b) have a follow-up dialogue option (maybe depending on the player's lewd or charm trait levels) where the player can recover from their initial mistake by apologizing to Samantha or saying something smooth that will make her swoon.