You’re the one making statistically unsound assumptions here. None of what you’re saying has any basis in actual fact.
Plenty of people are in relationships (formal) that don’t have sex with each other anymore. A few never had sex, but are in relationships where the social assumption is they did/are.
Plenty of people (including women) have multiple partners, some long term, some transitory. (Many to one). Sometimes they know of each other. Usually they do not.
Plenty of people have one or more partners of different ages (sex or relationship wise).
Plenty of people have no meaningful relationships (sex or formal) of any kind for long periods of time or ‘anymore’. Often by choice, sometimes involuntarily. I know several men who flat out ‘noped out’ in their 40’s because they got tired of what they perceived as predatory behavior. And at least one woman who did the same. All of them had been married for long periods of time.
Hell, one female sex worker can have anywhere from 20 to 100 clients (monthly) last I read on a regular basis.
It’s not that uncommon for some edge case men to sleep with that many women every couple months. I’m sure they’d be ecstatic if they could be paid for it, but male sex workers predominantly have male clients.
Many people consider things like this to be some kind of dating, or at least related/impactful to it. All of it interplays with relationships. The social expectation is that dating, relationships, and sex are all interrelated.
So what are you trying to say exactly besides ‘that’s all gross so I don’t want to believe it’?
If you think that’s bad, don’t get into the medical field! You won’t necessarily get the truth, but if you have even a decent idea of the STD transmission odds, it’s clear what the lies are!