Smooth moves at the summer camp dance

Today's the last day of summer camp and the group celebrated with a potluck and a dance. The dance just ended when I popped in with potluck chicken. I asked the boys, sweaty and flushed, if they danced.
"No!" Sam said, at the same time Jack said, "Yes!"
"That's great - you danced!" I was happy and a little surprised to hear it. Sam had been dreading the dance. Girls were involved.
"Did you dance with a girl?"
"NO!" both said emphatically, glaring at me in that creepy twin way.
"Cool," I said, pretending to be a cool mom. "So you danced alone or with each other?"
Sam piped up. "Yea mom, we danced!" Jack nodded in agreement.
Pause.
Then Sam continued...
"Well, we beat each other up during the dance."
Well done boys.