There are always recurring threads on MN about partners wanting less/more/different sex ... interesting piece here ...
www.nytimes.com/2018/04/06/style/modern-love-sleeping-with-married-men-infidelity.html?mabReward=TS2&recid=12sELcrRDq0BiHaXpsk8vtbH1xH&recp=0
Some of resonated with me based on my own experience (I've never slept with a married man, except DH).