I once got Jenna Jameson's first BG scene just out of curiosity, and I consider it by far the best of her scenes that I have ever seen. Randy West clearly has an unplanned cream pie while she is riding him. You don't see any jizz, but it's fairly obvious what happened.
As I remember it, she didn't continue to fuck him after he came, but it is an incredibly hot scene, and you may want to check it out.

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