When his wife returned, he asked her about the people on the trip in general, then casually asked her about the specific behaviour of the passenger he knew to be his mistress.
"She slept with nearly every man on the ship" his wife reported.
The disheartened man then rendezvoused with his cheating mistress to ask her the same questions about his wife.
"She was a real lady" his mistress said.
"How so?" the encouraged man asked.
Spoiler:
