Its all about communication. Jealousy is pretty natural, and is up to you as the photographer to ensure you gain your partners trust.
Someone feeling jealous is doing so because they do not have a clear understanding of what you are doing and that is perhaps making them feel a little insecure.
These insecurities can naturally make someone paranoid and self critical.
You need to identify with your partner and make a list of all things that may trigger jealousy.
Discuss these with him/her and build their confidence with regards to each point you have listed.
Ensure that your partner has control in determining what makes them feel secure about each point.
Clarify and gain their acceptance.
Take him/her along to your photoshoots so he/she can see the professionalism involved.
For obvious reasons, taking an assistant with you, will also help a great deal.
Be charming and hands on when required, but always be professional with the model, and let your partner see this.
As long as your partner feels secure about your photoshoots, then there is nothing to worry about.
What he or she is going through, is natural, but you have the power to avoid any potential jealousy issues.