It's not that you're jealous. It's that the person is annoying the friggin' crap out of you with that fake laugh and stupid fluttery eyelashes and hip swing so broad furniture keeps getting knocked over.
This spell can work for any genders of any of the people involved. Just substitute whatever pronoun for "man" and whatever other pronoun substitutions and you're good to go. And here's what you'll need for the spell:
Waning moonlight (or a waning moon moonspun chord if you're in a rush and no waning moon is available)
One bottle of our Stay Away From My Man! Oil
A "spell space" set apart specifically for this purpose with a good surface
A quart mason jar almost full of purified water
A cauldron (or other container set apart for the purpose)
Two tablespoons of vinegar
A wooden spoon
Photograph of the invasive person or some other pictorial representation.
Directions: Go to your spell space and under the light of the waning moon, pour the water, vinegar, and the entire bottle of oil into your cauldron without stirring it.
Now take out the photo of the person you want to stay away and vehemently tell that person to stay away from your boyfriend/husband while Xing out the person's image ferociously with the black marker. It is important to put all your feeling into this because you want that person out of your lives.
After you've done this, rip the photo into as many pieces as you can AWAY FROM YOU--NOT toward you and dump all of the pieces into the water. Then mix it all together clockwise with your wooden spoon.
While doing this, picture the face of the person in your mind and move close to the cauldron. Make "eye-contact" with the water as if you were looking the person in the face and then chant firmly, "Stay away from my man!" nine times.
Immediately after the last time you say it, spit directly into the cauldron and carefully pour the entire mixture back into the Mason Jar without spilling a drop.
Clean up your spell area and immediately drive to some place that represents that person to you, whether it be their house or a place you've seen them and then scatter the water all over it. (All the better if it's in their front yard, but if you can't manage that, another place that symbolizes the person will do.)
This part of it does not have to be slow and ceremonial as it needs to be done on the sly most of the time. You don't want to draw ANY attention to yourself here. Once you have scattered your spell water, walk away and DO NOT LOOK BACK.
And that is that!