This beast (oops, I mean guy
) reminds me of my FIL...well, kind of. I'll be talking to BIL and SIL about something I'm making, or SIL will be telling me about one of her projects, and FIL will say something out of the blue like..."Well, Lisa (her name, how coincidental...) can do X," totally off-topic. I just kind of pretend I didn't hear him, and he usually doesn't repeat it. I know he's saying it because he feels slightly insecure and slightly regretful that he married her. Long story short, she's the meanest woman I've ever met, and doesn't treat SIL very well, and he's aware, but she has his man parts in a vice and he's too comfortable to divorce her. So he's stuck.
Anyway, I combined a few suggestions for you: "Ho ho ho, DH, did you hear what dear ol' JOHN just said? He's SOOOOO funny! Tee hee!" *tally mark* "Hey John, that's 30 times you've insulted me today! You owe me a drink!" *giggle with other friend or DH*
That would mortify him, especially if you said it loud enough that everyone heard that you were keeping track. Or told them beforehand.