Being a Bedroom-Only Dom Without Worrying About Threatening Sub's Open/Poly Marriage
I've recently separated and begun the divorce process with my wife after a long marriage, which was open/poly for most of it.
My marriage was in many ways ruined years prior to the divorce, when my wife entered her first D/s relationship and we essentially went from open to poly. Her first D attempted to cowboy her (i.e., break up our marriage with young kids) and used his role as a dom to try to effectuate this plan. This D/s relationship ended when he went too far/got too obvious, and led to another relationship with a man who tried to do the same (more subtly and over a longer period of time), and the trauma of those two back-to-back relationships broke something in my wife regarding her desire for me that we were never able to heal, and stayed essentially co-parents and life partners with benefits for many years until this summer. There is more to the story (see my post history if you want to be depressed) but that's the core issue.
I'm not mentally ready to be in a monogamous relationship (i.e., I worry about potentially hurting a monogamous partner), but I thought that testing the waters in the ENM world (which I haven't taken advantage of much in recent years) would be safer. I've recently met a lovely married woman who I met as a third for her and husband, and I've seen her a few times separately since then. She has interest in me being a dom in the bedroom, which is something I've done before with some success (perhaps as a reaction to my wife's experiences), but at this point in my life I am extremely paranoid about the potential for a D/s relationship to do damage to an established marriage, even a poly one.
The physical aspect is fine, but I've caught myself having to call time when she says things that I should be fine with, such as elevating what we are doing (or what I'm doing to her) above what she does with others (which is almost vanilla play-talk), and on one occasion it really took her out of the experience. I want to give her what she wants, but it's almost like some part of my brain is thinking I can't trust her to do this responsibly, which I acknowledge is extremely offensive and paternalistic, particularly as she has given me no evidence that this is the case.
I also have a cognitive dissonance that is very troubling to me. On one level I enjoy her submission and her elevation of what I can do to her, but on the other it horrifies me. I think I get some sick validation being implicitly praised and treasured for the sexual aspect of our relationship (which never really recovered with my wife) and for being in the opposite position as in my own marriage, while at the same time the sense that I'm harming her marriage makes me sick. I've had plenty of other partners over the past decade, but this issue has never come up before.
While this relationship is very casual at this point, I would like to maintain it if I can. Does anyone have any advice how I can give her what she wants without guilt/shame? Obviously I can just tell her that D/s is off the table for now, or break up, but hopefully someone has some sage advice. I truly appreciate that I am the entirety of the problem here, just to be clear.