i think this is the case too. he is her Dom, and she really craves being the sub. Ask her if she was "collared". Sounds like she is in the category of "Married, but owned by another man".Something is off here. It doesn't add up.
this might be accurate but not the way you think it is. She's subcommunicating. No way she had a 'regular' affair with this man. So-called normal sex. No way. Attractive 38 females don't do that with 70-year-old fat guys for X years. Maybe a one time thing. If that. She could have gotten a much hotter guy for a regular affair partner. Yes he had an emotional hold over her. Your wife sounds like a submissive woman. Is she? the old man a dominant figure. Is he the kind of guy you wouldn't have wanted to fk around with when he was somewhat younger?
I think this guy may have been her Dom and she was his Sub. If im right, he likely commanded her to put that photo up. Her duty was to obey.
Not sure how you can break her out of that. she has had this relationship for many years, she must absolutely love the abuse. You can get the guy off of your property (i am thinking restraining order here). but she is going to crave being sexually abused. Look into what that means, but if you are not interested in becoming her Dom....not sure if she will ever be happy going back to Vanilla-only sex with you.
I personally would be concerned about how much of a masochist your wife is. She may be into physical things, like breast torture, that you could never get into. Have you noticed any odd injuries, puncture wounds, evidence of whipping or caning, or other bruises on her body from being tied up or abused?
Something worth looking into...get an account on Fetlife, and search locations for your town to see if she has a profile on there as a sub, or if this guy has a profile on there as a Dom listing your wife as someone he "owns". there might be pictures on there of your wife.
Or, if you can live with it, let her keep the dom/sub arrangement going, and accept the vanilla spouse sex role you have in it.