Oh sweet heaven,
I hope this is not a real post. If it is, then you need to get help, right away. SERIOUSLY!!! I know a man who regularly calls me to complain that his wife is prostituting herself cheating with younger men for drugs. She's nearly 70 years old and drug tested for her job, and honestly, although he says she is beautiful and always turning younger men's heads, she is NOT. Not saying older women are not sexy, cause they can be, but she is not in that category. Never has been. Still, about every 6-8 months or so he calls me with the most elaborate tales of her deception. He is very sincere, full of despair, and completely in need of help, as I think you are. If this is a real post.
A woman, who is your wife, refuses to have sex with you on occasion, and does not give you a reason?! Here's the reason: It is 2015, women are no longer property, and its her body.
Next, if she's nearing menopause, and even young women can enter it early, or some other medical reason, she will not want to.
Next, she may have a psychological or emotional reason that she does not want to.
Finally, if your go to issue under this circumstance is to accuse her of fantasizing about past lovers, then perhaps her issue is you. I'm not being mean spirited when I say it. I genuinely mean that you may have just gotten on her last and final nerve. If a woman is sick of you, she's not sleeping with you if she can help it.