I find it absolutely fascinating that you have phrased this question in such a way that it only addresses straight, monogamous women. Surely it has not escaped your notice that there are lesbians, bisexual women, and even *gasp* men posting on this board?
In answer to your question - although you did not ask me - my level of physical contact with someone is directly linked to my emotional intimacy with them. Gender and sexuality don't come into it.
I don't care who my wife touches or how/why, because I trust her.