OK, so far, so good. If it walks like a duck, and it quacks like a duck, it may be a duck.
So if I’m understanding you correctly, you are not labeling this punching game as wrong, or immoral, simply not your cup of tea. Cool. I know people who are into some serious S&M, and though I’ve been known to take (and enjoy) the occasional spanking or two, I’m an amateur compared to them.
My experience says otherwise, but continue…
One should understand the rules of the game in which one is playing.
If casual sex is being done in the confines of a committed and monogamous relationship, and the expectation is that the relationship is likely to grow and bloom then adding sex may intensify feelings. In fact, I’d go so far as to NOT label this as ‘casual’ sex in the first place, as there’s nothing ‘casual’ about it.
OTOH, If the sex is married couples fooling around as a group with the expectation being when it’s over, everyone goes back home and life goes on, there’s no reason for it to do so.
I’d even say if it’s NOT the expectation of ALL parties that it’s ‘just sex for fun’ then whoever doesn’t think that is not really having ‘casual’ sex in the first place. Not everyone is emotionally capable of casual sex, and those that are not should not partake. Then again, not everyone is capable of jumping out of a perfectly good aircraft, even if they believe their parachute will work.
Different Strokes. No pun intended.
One need not have any sort of sexual activity, real, expected, hoped for, or otherwise to have this exact same scenario play out.
Sexual issues are but a single item in a very, very long list that can cause or contribute to this phenomenon. And what’s your alternative, forcing a couple who have concluded that they hate each other to nonetheless be forced to live and act as a married couple?
You have not shown that in the least.
Now, I CAN give you a secular/quasi-religious perspective that tends to show why sexual promiscuity is something that should be avoided, at least in days gone by.
Because it’s dangerous! And God will punish you for it.(Or, was.)
Back in the day it’s a factual statement that it was literally a dangerous activity, litterally akin to playing russian roulette, and you play that game enough times, it’s just a matter of when you’re going to lose, not if.
However, our medical technologies have changed that. Most of the hideous sexually transmitted diseases that plagued mankind from it’s inception until but a few decades ago are now nothing more than nuiscances, requiring nothing more than a shot or two to completely clear up. No form of contraception is 100% perfect, but stack a few of them together (say pills, condoms, and withdrawal combined) and you get close enough that the whole unwanted pregnancy thing becomes very, very rare.
So, yeah, 150 years ago you were dumb to be promiscuous. It was likely even more true 1500 years ago.
But not so much today.