If a guy resists, which often happens, she will seek alternative ways of convincing him, making him see the light. Usually, one of the first tactics is the threat of him losing her to another guy. She will do things that will make him think he is about to lose her. There are other guys out there who will make her happy, and she’ll find ways to let you know that. Women are masters at playing the jealousy card. They know men’s egos can’t stand the thought of her being with another guy.The thought of her sucking another guy’s dick would drive them nuts, especially when guys are young and very possessive and insecure. Women know this and play it to the hilt.

This usually works enough to get the guy to the next level, which is some sort of commitment.

What it is about the thought of a girl being with another man that induces a feeling of being betrayed in most guys?.

And why does the pride of a man suffer when he discovers his partner is sleeping with another guy?

I think this analysis is missing 1 part of the puzzle. And that it's just as often the case, and that is that the guy (especially younger men) fears losing a sex partner and that it will take him a long time to find another sex partner/fling/one night stand/etc..
So in that case it's not so much jalouzy imo, but more fear of entering a dry period.