I don’t believe at the age of 50 it’s about sex at all. Your scenario sounds made up. I would bet if you really asked woman that age ‘why’ they switched teams, sex would not be the #1 reason.
Many, if not most, women have gone through menopause by the age of 50. Sex drive is diminished.
My scenario is not made up. I lived in Portland, Oregon for years. One of the biggest homosexual populations in the country. I know many lesbians. Most lesbians that I know like multiple partners.It is normal lesbian behavior for three lesbians to be living together, sleeping in the same bed. They think nothing of it. It is sex to them and nothing else! Most homosexual men like to prey on young teenage boys and the more the merrier. Homo men do not like to be tied down to one man. That’s why the AIDs epidemic was so bad. Predator homosexuals sleeping with anything they would jump in the bed with them.