>>105762372A sexual intercourse (and intimacy in general) creates a very strong bond and in a long term relationship it strengthens it.
The more casual sex you have, the more you train yourself to desensitize yourself to the bonding effects of sex and to the breaking of that bond.
This directly causes a significant reduction in your ability to form long term relationships, because "temporary and easily breakable" will be how relationships are for you, subconsciously and emotionally.
Multiple studies have shown that the number of previous partners inversely correlates with satisfaction with your current relationship.
How are you supposed to settle down with the one special person in your life, if said person is actually the 5th? Any little bullshit and you'll be thinking of divorce, which is why relationships today are much more frivolous, divorces are happening at such a high rate, and single mothers are everywhere.
Everyone has known this throughout history (ask any man if they'd prefer to make a promiscuous girl the mother of their children, vs a girl that's exactly the same in everything but isn't promiscuous; everyone understands that a whore doesn't make for a good long term partner), but now, because of baseless ideology, people are made to think that such obviously egregious behavior somehow doesn't have consequences, then they're surprised when their relationships don't work out.