"Heck, my mum said that more guys flirted with her as soon as she had an engagement ring than at any time before. Sometimes they want to test their power to charm without any possibility that it will lead anywhere."

As an aside: I have always been mystified by what qualifies as "flirting" - often I find that what I consider simple politeness is interpreted as "flirting" by the opposite sex. I find that both men and women interact differently with members of the opposite sex when they know them to be out of bounds - very old, very young, married or engaged. Perhaps what we call "flirting" is our natural way of interaction, restrained most of the time by our need to not lead the other party on. Perhaps that need to not lead others on is itself a cultural imposition. I wonder how relations between the sexes might compare in societies where casual sex with strangers is not condemned - might the cluster of behaviors deemed "flirting" be considered simple decency?

I wonder if your mother did not encounter guys testing their ability to charm, but simply guys who could finally be themselves around her?