I think that it is somewhat more problematic to 'treat' one's girlfriend(s) to extracurricular sex when we are younger. It can produce both stronger emotional and physiological reactions in both sexes. In the male it can create an emotional anxiety that there could be an alienation of affection. There is also a strong physiological response which results from the fact that as primates, humans have sperm competition. This latter phenomenon can really wind a fellow up.
For women, I think they experience a stronger emotional bonding response when they are younger. I don't know of any studies, but my guess is that oxytocin production declines during and after menopause. I was highly amused by one girlfriend who was in her mid 60s and I was treating her to younger male escorts. (Funny how so many of you gals seem to really appreciate a man 20-30 years younger 😂) In any case initially she insisted that she couldn't have sex with a man, even an escort unless she formed some sort of connection. After a few experiences she said to me, "I have a confession to make. I discovered that I don't need a connection. I just like to get banged."
Like so many women though she would not have done any of this on her own but having me create safe, controlled environments in which to push the envelope made these experiences especially fulfilling. I think that more women would indulge in this way if that were the case.
So, if you know any 50 somethings or 60 somethings that would like to enjoy some new personal adventures you know where to find me!