I would guess a good % of women don't orgasm with bulls when its not a long-term partner, for a variety of reasons. Probably the biggest factors are the degree to which the woman orgasms from psychological arousal vs. physical pleasure and how nervous she is during the encounter. If fucking a stranger or being watched by the husband is a huge turn on and the wife is relaxed, then yeah, probably tons of orgasms even if the physical aspect isn't amazing. If she can't relax and is worried about the first encounter, what her husband might be feeling, STDs, worrying about what the new man thinks of her, whatever, then its going to be hard to cum, even if it feels great.
I also imagine it is common to drink ahead of these encounters, especially if the woman is nervous and I know at 40, alcohol can make it very hard for my wife to cum sometimes.
Even if the wife doesn't cum though, I am sure the encounter can still be very enjoyable due to the experience of another man and the excitement it brings to the relationship.