I can’t say for sure but I suspect Stacey has cum nearly every time - probably rare when she didn’t. For one thing she’s highly sexed and enjoys fucking. Plus she is turned on as much as I am by having sex with an acquaintance - the foreplay and build up is immense: the excitement of meeting for the first time, the flirting and first kiss, touching, usually dinner and a few drinks, followed by the sex act. By time she gets in bed she’s ready.