It's not immediately visually obvious.

But only one of the great big sprawling pile of kissing, snuggling, various-other-things-doing Jokers looks up and waves at Nathan with a call of, "Sweetie!"

(At some point since he went in, he's put his scars back on. That makes him one of two who has them. He was in the middle of making out with the other one when Nathan walked in.)