Simple is not the same as easy. If a couple is having intractable sexual issues (or seemingly intractable), the solution, or nonsolution is simple. Seemingly intractable assumes no medical problems, no hygiene issues, no weight problems, etc. The problem is that that one partner is ld and one is hd. The simple solution is that the ld partner starts giving it up much more than they are comfortable with. The ideal frequency is a compromise in the middle of what the hd and ld partner prefers: ie- hd wants is 20 times a month, ld wants it 2 times a month, do it 10 times a month.
But here lies the rub: the ld partner has to either fake it, or make it. In other words, they have to do what it takes to enjoy themselves, or do a very good job faking that they enjoy themselves. Problem solved!

Short of that the problem will never be solved. It's divorce time, lump it and live with it time, or come to a mutual agreement about finding some on the side time.
Game over.

sop