The main rule of the hookup is letting your casual partner be, without interrupting their personal borders. It’s only natural if they still want to look single in public, even right after having sex with you.
Developing this degree of respect isn’t easy at all. Only people with an experience and a certain psychological help can manage that. The sooner you learn to control yourself, the better your sex will become.
Do not press your hookup in any way when you’re out with other people. The jealousy isn’t appropriate, since you two aren’t the real partners. Do not flirt openly either, it doesn’t look too exciting to them.
The independence should be your favorite word and style of behavior. It really kills two birds with one stone. Your hookup starts to want you more and also you create the safe space around you two.
It surely takes some time to learn, but you’ll be much rewarded when you do that. The next hookups will be attracted to you more as well, feeling this special atmosphere of inner strength and mystery.