About a year ago, I went for an FBSM session with a provider in the East Bay. Her ads as well as my conversations with her were clearly no GFE, only FBSM. And I was fine with that. However, on the flip, I could see she was getting quite excited, and her clothes came off, a rubber was on, and she was riding me. A full GFE!
When I left, she made sure I understood that this wouldn't happen again. (I've seen her again since then, and it was purely FBSM.)
My question to providers and hobbyists: has this happened to you?