Two related things are very difficult to undue if you are the HD partner in a sexless marriage.
First, there is the expectation that there will be sex within the marriage relationship. As noted above, this is both an explicit and implicit exclusive part of the R.
Second, w/i the sexual context, there is an expectation that sexual frequency and intensity will meet some sufficiency level. These are often conflated. You can have the first expectation met without the second. You cannot have the second without the first.
And for some women, not even the threat of "losing" their partner (and I don't mean the explicit threat of walking away, I mean that in the way that the HD partner will give up and seek what they desire with someone else) will move them to seek some level of resolution.
For example, I have lost over 70 pounds in the past 5 years and am back to the slim, trim weight before my sex life dissolved before my eyes. She evidently sees that as a threat (that is a story for another thread). But she hasn't been willing to do anything about it.
The Captain
Last sex: 04/06/1997 Last attempt: 11/11/1997 W Issues "No Means No" Declaration: 11/11/1997 W chooses to terminate sex 05/1998 I gained 60, then lost 85 pounds. Start running again (marathons)