Tl;dr:11 yo daughter gets beta to take full-face slap in front of friends for chance to orbit.

We are throwing a kids party. The kids were given a certain number of invitations to share with friends. My daughter (11 y.o.) has lots of girlfriends that hang out with her at our house. There's a boy (classmate) who's already orbiting her and her friends.

Long story short: He stopped by the house when my daughter and her friends were here. He asked if he could be invited to the party. My daughter literally dangled an invitation in front of him, then pulled it back and said "Ill let have it, IF you let me slap you in the face as hard as I can". Her girl friends squealed with glee at this. The boy said "uh, ok I guess" and my daughter proceeded too full-swing bitch slap this kid. They all howled with laughter, she handed him the invitation and made him leave.

This boy is obviously socially awkward, adopted, and has a mentally handicapped non-bio brother. I'm disgusted, but post-TRP not surprised by this behavior from my daughter. What shocked me was observing this behavior in one so young.

I'm at a loss as to how to approach it. I'm thinking of framing it from a 'just be a decent human being/golden rule angle' but damn.

Lesson Learned: AWALT, even at 11.

Edit/Update 1: To clarify, I overheard this through a window. Daughter didn't know I was watching. Discussed with Wife, agreed that as punishment, she can't be allowed to participate in party. Called daughter in, told her what I heard/saw, got predictable (juvenile hamster) response: denial, trickle truth, attempted blame shifting (it wasn't my idea, someone else told me to do it!), then apology. Told her not good enough, no party for her and all her friends. She cried. We then had a long discussion of how the boy must be feeling, would you like to be treated like that, etc. I warned her that if I get the slightest wiff of her trying to blame the boy/retaliate for any of this, she'll regret it. Boys still invited, as I have sons his age he can participate with.

Edit 2: For all you judgemental pricks out there blaming me for creating demon-spawn, you don't know the half. I'm the sane one working hard to get these kids right. He mother (my ex) is a dark triad drug addict who successfully hid her double life from me for years. She still has contact with them thanks to the magic of being mommy & the family court system. Go fuck yourselves, you have nothing productive to say.

Thanks to users like /u/pantsonfire and /u/darthexero for pointing out the girl group dynamics and whoever suggested using the social shaming tactic to correct her behavior.