I actually believe this act in hetero relationships would help balance out the love, intimacy, and a variety of other things. E.g. it would allow the female partner the ability to feel what it is like to take a person, and for the man to be on the receiving end learning how it is to be filled.
Also remember, with the right insert or an insertable strap-on (feeldoe e.g.) it is very much possible for a woman to orgasm while doing that. Think about that angle, the wife/female partner pounding out an orgasm with and too her husband/male partner.
It would also help with the birth control angle too, especially since if the women hits the p-spot, the guy maybe in for a very big surprise ….