Chaperoning Chaos

Last weekend, I was chaperoning a school camping trip for my class. One of the girls, a bright student who's in her twenties and has a mischievous streak, decided to push boundaries when no one else was around. We ended up in a tent alone, and before I knew it, she was acting like a little kid - whining, giggling uncontrollably. I let myself get swept up into the role of being her 'daddy', setting some playful rules for her behavior but also letting us have fun together. Afterward, I'm left wondering if this is normal for an adult-to-adult dynamic? Any thoughts on this kind of play?