That is okay.
I think these are very individual things that are impacted by many factors. But for us it has all been beneficial.
For me NRE with Mya didn't only affect my desire for her, but also my general sex drive. Thus, there was an increase in quantity for the infatuation period, but that effect was obviously just temporary. Alec tends to want sex somewhat more than I do, so the increase in my libido was welcomed by the both of us.
I am in a long distance relationship with Mya, and I guess that allows me to see some of the effects more clearly. I have a completely different sexual dynamic with Mya than I have with Alec. I get to express different sides/aspects of my sexuality with her, that I can't with Alec (and that works the other way around, as well). I feel sexually most complete with both, and when both of them are available to me, I actually want more sex in general.
My sexual relationship with Mya doesn't include either of our husbands, they don't participate or watch. It also doesn't feel comfortable for any of us to discuss the details overly much, at least not with the purpose of arousal. Obviously I am fine with anything that goes on in Alec's head, that doesn't bother me in any way. He does enjoy thinking about me with women, in general, but it seems that it doesn't work in an entirely similar way when it's a girlfriend instead of a more casual thing (we are open for that, too).
Have you considered the possibility of your wife exploring her sexuality outside the context of a romantic relationship? Would she feel comfortable with having casual sex, or being intimate with a friend? How do you feel about that? Not that you need to be open to be poly, of course.