You misinterpret the way i use "teach". i don't mean it like he should hold a grudge or have his revenge. Matter of fact i'm against holding grudges because it's self-inflicted mental poison.
When i say teach, i mean it in the sense that you teach people on how to treat you in the future. it's cause and effect. If she's being manipulative, he sees she's being manipulative and he rewards this behavior by opening up, she learns that when it comes to Steve Piffler, getting him to open up can be achieved through manipulation. You definitely don't want to teach that to ANYONE (let alone your wife). He should only open up to her when she's truly sincere and honest (and it would be clear in his gut and intuition). That way, you teach her that to get Steve Piffler to open up, you have to be sincere, honest and humble (and not do it as a tactic/strategy). THAT's what you want to teach people when it comes to how to treat you (and even then you should be careful.)
What good is a marriage if it's founded on games and manipulations?