I may need to say something that is (seemingly) nice about someone, but I’d prefer it be very subtly backhanded or nearly believable hyperbole.
Edit: I realized that I was imagining something like how the Colbert Report was done where it’s easy to believe I’m agreeing when really I’m spoofing.
If you don’t say anything, they assume you agree with them. It’s a fine line between letting them know you (maybe respectfully) disagree, vs. actively debating, but in some cases I think it’s worthwhile to try to let them know you aren’t inside their bubble. Agree outright dickishness is unhelpful, but so much depends on the specifics of the relationship and circumstances of delivery.