Yeah, Jaina was hoping for a little petty retaliation. There are also some factors of...blind spots in Jaina's shame and simply being willing to play dirty to win things (Long story short, she's a Solo and she takes after her dad).

Beyond the "you're dancing with my boyfriend, what can I do" thing, Jaina actually was just analytically thinking. Okay. Kissing Mitchell is a sure thing, I can probably get the romantic kiss task out of him. If I also man up and kiss someone I'm mad at, I can also get a second point toward winning, easy as that. (Analytical thinking is just part of how she rolls in win or lose situations sometimes; we even see her mentally stepping back in the middle of a life-or-death lightsaber duel with the boy she wants to be her boyfriend to think about how she can fix him as if poke here and prod there and everything will be fixed, as with fixing an engine)

And it's a lot easier to suck it up and go kiss someone she's mad at in light of recently being hit with remembering deciding that she has to kill someone she loves.

Finally, Judith was one of the better choices for who was at the party that she really didn't want to kiss. XD

One of my favorite questions, anything you'd like to see our characters do in the near future?