The only type of role playing between two legally married adults that could be considered immoral would involve sinful behavior such as homosexual , violent or adulterous activity.
I honestly don't know how God feels about it. I know that I personally don't have a problem with it. As long as it's between consenting adults, I'm not sure what the downside would be. If it's a perversion, it's a really vanilla one. It's something that, as far as I'm aware, isn't generally addressed in Scripture or mainstream sermons, and is hence left up to the individual.