There is no secret:

It’s not the first time I’m wondering why. Well, why often it happens that when a girl is looking for one-time sex or “free relationships,” she gets only romantic princes, which either immediately include “Oh my god, I’m a thread!”Either they fall in love and get married. And when a girl is looking for a serious relationship, love, maybe a family - she is found by brave sailors who need sex and as little responsibility as possible?
Discover the secret, what is it? What are we doing wrong...?
-
This is the man’s logic in action: "Doesn’t want to get married? This is a cool girl, I marry, urgently!" vs. "But she wants a relationship, run and run until they have caught up and have not stroked the lamb!"