Well, I was the typical low desire W, so I hope my point of view will help. My H wanted to ML probably 3x/week on average. I would say "no, later, ok, or go ahead." I always thought that as long as he eventually "got it" everything was ok. I actually liked being chased as I felt "wow, he must really love me", even though I am not a skinny minny (I have ranged from a size 9-14 over our 8 yrs. of marriage and post kids) and have fair to poor body image which has added to my lack of desire.
Anyway, I never understood that he didn't feel loved because of my "rejection." All I heard was that he wanted more sex.
Well, when the &^%$ hit the fan and we talked more about his feelings of rejection, etc.. Then I got it. My point is, I wish H would have told me his FEELINGS re: ML, I just never understood the deep emotional connection that he needed and was lacking from me. Now my LL is also physical touch.
My H and I are S and I pray our marriage will be reconciled. I truly believe if sex wasn't one of our HUGE issues before, we would not be where we are today. My suggestion is (when the time is right) to write S a letter explaining your FEELINGS so that she may fully understand your POV.