I see what you mean. She knows you well enough to know that it would be an empty threat.
I'm kind of surprised that counseling hasn't helped your situation more simply because it should have "disclosed" how wacky your W's stand on the sex issue is. I mean if you guys were at a social gathering and the subject of sex came up and you were to say "Well, we haven't had sex for six monthes and W threatened to call the cops if I ever touch her boobs without permission again." your W wouldn't be at all embarrassed to have her outlandish behavior exposed? Maybe you ought to start writing people letters like CSW did about his W's affair.
Dear MIL,
I thought you ought to know that I am strongly considering divorcing your daughter because she hasn't had sex with me in 6 monthes. I feel like I do my best to be a caring, responsible husband but I am at the end of my rope. I have received the impression that you have been somewhat supportive of my wife's negative view towards men and sexuality but I thought I should give you the opportunity to advise your daughter otherwise if this is not the case. I can understand that you had difficulties with her father given his personality and attitude but surely you can see that I am not like him and counsel your daughter in a positive manner unless you prefer to see her live the rest of her life in solitary bitterness with a permanent grudge towards half the human race.
Love, HD
"Tell me, what is it you plan to do with your one wild and precious life?" - Mary Oliver