Another important point!
When you show absolutely no jealousy, your partner might perceive that as a sign of total desinterest.
They can interpret that as "You don't care!".
It highly depends on their character and their own power level.
Not expressing jealousy at all if you can and if your relationship or security is not threatened is definitely the way to go, but...
If he needs it, showing him playfully that you can play the jealousy game validates him as well - He thinks: "She is ready to fight for me! I like that!"
Being jealous when it is appropriate is usually ok as long as he doesn't see you enslaved by an emotion you don't control.