Anyone with common sense knows this, and yet, there is a powerful public delusion that everyone can just screw anyone with no negative personal or societal outcomes.
Among the FR population, whose average age is quite high - I'm a youth at 53 - it is only men who proudly proclaim their promiscuity, but I understand there is more gender equality among young people.
The conflict from the males comes from the expectation that they are supposed to support children who are not theirs, and support a woman when they might not get equal access to sex with her.
The only way that works out with the guys, is when they pay to support her on a per-transaction basis (prostitution). Now, prostitution has been workable on a long-term, historical basis.