This is kinda embarrassing so I'm using a throwaway. So today I was leaving the cafeteria and then I bumped into this girl I know outside her room and started talking to her. Then a guy friend of hers came over and handed her a poem he wrote and I started cackling maniacally and went on my way. She ran behind me and before I knew it landed a swift sidekick to my butt. I turned around, smiled, and said to her "Nice kick Jessica" and she said "Yeah, I've been working out" She then went back to the guy and said "Wow, what a nice poem! Right, DarthFederer?" while looking at me. I weakly said "Yes Yes" while my hands were rubbing my butt. Then I said bye and continued on my way. What should I have done in that situation?

Edit: It was a playful kick.