Were mistress and wife faithful

Wanting to find out if both his wife and his mistress were being faithful to him, Gary decided to send them on the same cruise and question each one later about the other's behavior.
When his wife returned, he asked her about people on the trip, casually inquiring about the passenger who was his mistress when she mentioned the woman. "Oh, that woman slept with nearly every man on the ship!" his wife reported.
Unhappy with this information, Gary planned a rendezvous with his cheating mistress and decided to question her about the trip before confronting her with what he knew.
Once again, he carefully inquired about the woman who was his wife after ascertaining that they had met.
"She was a real lady," his mistress said.
Gary's spirits picked up. "Why do you say that?" he asked.
"She came on board with her husband and never left his side."