I am also a married SD and have been in a very happy SD/SB relationship for 3 years. I have been married for a long time and she stopped wanting sex 12+ years ago. I have never told her but I think she knows but as long as I am not blatantly obvious, it is don’t ask/don’t tell. So the SR keeps me grounded and sane and actually helps the marriage. Several other SDs I know are in the same boat. Sexless marriage for several years.. I suspect that many SDs are in the same boat.
Recently started SR with a married man, and I wholeheartedly believe that going down this route is helping his marriage. His wife has lost interest in sex, and they live far away in the countryside (he commutes to my city) where there isn’t much to do. With me he can be his fun, younger self again, and then return home to his family without resentment or unmet needs.
My preference is married men because they don’t overstep boundaries so much. I don’t get peppered with text messages, my weekends are my own, and neither one of us is expecting more from the other.