My wife is faithful to me, but only in ways that aren't sexual.
Care, comfort, support, etc. And that's what I want, really.
When we met 30 some odd years ago, I told her she had COMPLETE sexual freedom. She could fuck who she wanted, when she wanted, without asking me.
I meant it then and I mean it to this day.
On the occasions that she has, I've never considered it as being unfaithful.
She has a friend from high school that she has fucked a few times. Now, HE wants her to be exclusive to him, but had to accept me, and even he knows the reality is he can't 'control' her. But, if he could, he would want to keep her to himself.