It surprises that some people describe this as some sort of display of affection. They figure that if their partner wasn’t jealous then that would somehow mean that they weren’t loved by them.
This is absolutely clownshit crazy to me. It’s controlling and manipulative. It creates unnecessary drama and fighting. It transmits a message of a lack of trust in the other person. And to be honest, it’s demeaning. If my girlfriend cannot trust me to be around other attractive women by myself, then it implies that she believes that I’m either a) a liar, or b) incapable of controlling my impulses. In either case, that’s a woman I do not want to be dating.
What You Should Do Instead: Trust your partner. It’s a radical idea, I know. Some jealousy is natural. But excessive jealousy and controlling behaviors towards your partner are signs of your own feelings of unworthiness and you should learn to deal with them and not force them onto those close to you. Because otherwise you are only going to eventually push that person away.