When I was less experienced, I was part of an event where a guy set up his unaware wife. The details aren't all that important - when I entered the room, hard and ready to fuck, the wife was in a state of shock and disbelief. Her husband had conveyed a bunch of rules to me, including:
1. Condom only, straight fucking
2. No kissing, no oral
Once the wife got over the initial shock, and things progressed, she broke all her husbands rules, removed my condom, totally got into being bareback fucked, and demanded that I cum inside her. She went completely wild, kissing, sucking, fucking while her husband squirmed uncomfortably in the bed side chair - he finally freaked out when she took my cock ass to mouth, calling a halt to things. They got in an argument and left. I'd say it wasn't what he expected at all. Her take on it might've ranged from "giving hubby what he wanted" to actually getting into fucking a strange man - I'll never know.
A few months later the husband contacted me again, told me "this time she's ready" - I passed because of the negative parts of the first experience.