How would you react if someone you went on a date with asked to be your slave?

Has this ever happened to you? The situation is we work together. I'm in a new role which means we interface more often. There was some tension. I just noticed he was rude and snappy all the time. Finally, we had this major blow up in the office over something really stupid. I pretty much went off on him about how he's been acting. He completely folded, apologized, and said I was completely right and started to be super nice and helpful, which I obviously liked. Then we're at lunch. He goes bright red and asks me. I just sat there. I had no idea what to say.