Honestly, I don't think girls or guys for that matter should do it but it is one of tactics people use these days to get into a relationship, nowadays. I'm saying this as a mere observer who has never been in a relationship (and not planning to) but has seen friends do so, in high school.
I can understand the action to some extent, since for person X it is a good way to gauge potential partner Y's, interest in X. But since cheating, infidelity and etcetera and etcetera are so commonplace now, and everyone is psychoanalysing every potential partner and their actions for those signs, the action is counter productive since it has the consequence of showing potential partner Y that person X isn't genuinely interested in Y since they are flirting with others, even though they have an interest in them.
But the fact that girls I used to know in high school would say this as a good tactic to gauge interest in potential partners, that means that it has worked for some. Some probably being a niche minority, whether they be in high school or grown-up. For me though I don't see the action of making potential partner 'jealous' such a good idea since the consequences of said action in today's society are rather heavy. Just shows that person has insecurity issues, rather shallow, suspicious and what not.
So really I just say this to the people I have given advice for and future ones, do what you want do but think about possible pros and cons of said actions.
