My wife enjoys rimming and Anal Sex as much as regular sex and she is usually "ready" for it. However, one evening we were just horny and after rimming her for entry got going and then she had an accident. I would not stop the Butt-fucking, just kept on reaming her. We both climaxed extra-hard and she later told me it was "so naughty" how I just kept Butt-fucking her anyhow. We showered together, which led to another moment of fun and thought nothing of it. It added a "primal" element to it and was fun because it was spontaneous.
Others?