We went from friends to something else in one afternoon [FM] (a bit of a long read, maybe?)

I [21F] went to hang out with one of my best friends [24M] earlier today. We had a coffee, talked about our lives, went ice skating and returned to the coffee shop at the mall to keep the conversation going. On our way back to the mall, we started talking about how much we trust each other as well as a little bit about our past sexual experiences and kinks without really planning on doing anything about them (or so I thought), but while we were drinking our last coffee, he striked: