My grandparents are like that. My grandfather wants to have at least some kind of emotional relationship with her, but she can't stand him. She needs him to help care for her, he likes the respectability of being her husband, and both would lose social standing. They are weirdly dependant on each other. To me, it's horrible, but they do it for their reasons. This has been going on for the last 20 years, and I doubt it will ever change.
Me - Mostly mono female, 39 yrs old, married to Leo.
Leo - Poly bi-sexual male, 37 years old. Married to me and looking.