If someone is truly "yours" than you can't or shouldn't be jealous that someone could take them from you. And even if that happened it means that person was never "yours" to begin with.

The definition of Protective in the context of this discussion can vary. If you are going as far to keep people from your partner and limiting their social life etc than that is toxic.

If you are simply wanting or hoping to keep them safe in a more reasonable manner than that is a different thing altogether.