Jack is very late for first date with Jill. Bob runs into Jill. They chat a little, then Jack shows up. Bob says something nasty to Jack about being late so that Jill will defend Jack. Jill does defend Jack, and they are both mad at Bob, but go on their date and quickly forget about him.
1) if Bob did this intentionally to deflect Jill's anger so the date would be more fun, it's entirely different from if Bob is just a jackass who's mean to everyone in sight, even though it's the exact same physical action.
2) Bob does something apparently nasty, and must pretend to mean it for it to work (until the next day, when he could explain if they are still mad at him), but it seems to me a good thing to do.
BTW this situation is from the anime Kare Kano (His and Her Circumstances) which I quite like.