Why do girls often trying to make their boyfriends jealous?

I've been in a relationship and my ex girlfriend herself has tried to make me jealous in so many ways. Not talking to me , but talking about the same thing to other people cheerfully. Showing me screenshots of guys (temporary fukboys that message literally every girl they see) who dm her, of them proposing her and trying to flirt and all.
But even online, I've literally seen posts of girls asking other girls advice in how to make their bfs jealous or feel down
And they get flooded with golden adivces as well
(1) tell him his passion&dreams r stupid fantasy
(2) tell him that u don't like his hairstyle, but appreciate other guys with same hairstyle
(3) when he's telling u something enthusiastically, just cut him in between saying"okh i get it"
I mean whyyyyy sooo
U say u love him, u don't want to leave him.
U want to be with him, but still wanna do these things to him.
what r u trying to test? Is he has emotions? Does he cry? How long can he stand the suffocation?

by the way my girlfriend has loved my more than anything and so did i (don't judge her based on her intent to make me jealous)

And by the way if is there any other guy who has felt the same?
Why do girls often trying to make their boyfriends jealous?
Add Opinion