Hi, Carolyn:

So, I am dating this guy and I’m in love with him, and I know he loves me back.

But I can’t, I absolutely can’t, stop getting jealous of his ex-girlfriend. He still talks to her because she has problems and he helps her through them. Whenever I know he’s talking to her, I see a picture of her or even hear her name, it makes me sick to my stomach.

I know why I’m jealous. It’s the stop-being-jealous that’s hard for me. I’m jealous because she met him first, she always gets his attention when she’s in distress, and she’s pretty. Just recently I just watched an old video on her YouTube channel, and my now-boyfriend kissed her on-screen and I just couldn’t watch anymore.

We plan to spend our lives together and to move back to her city. Once we do, I’m scared she’ll go after him; he told me she’s one to start fires. Meaning, she’ll try to take him back at the first opportunity.

I don’t know what to do if that happens, nor do I know how to get over this jealousy, which will last until he proposes. What do I do?

Keep getting jealous

Do I even need to say that proposals don’t magically render couples impervious to outside attractions? And, jealousy isn’t some unpleasant virus that will go away with rest and orange juice. It’s a systemic warning sign, and it won’t go away until you pay attention to what’s triggering it.

If you’re jealous of any attractive woman within 10 feet of your husband, your trigger problem is your own profound insecurity.

If you’re not otherwise jealous, then please respect your warning system enough to consider that she does pose a threat.

Why? You listed three reasons, but with apologies to William Peter Blatty, there is only one: She always gets his attention when she’s in distress.

Meaning, she’s in control.

If your boyfriend were resistant to her appeal, she could try to “start” all the “fires” she wanted to and it wouldn’t matter. And, too, if they were actually friends, giving and taking, and including you in their friendship, then you’d have nothing to fear from her. Exes who don’t have ulterior motives can make lovely and thoroughly nonthreatening friends.

But you’re talking about puppetry: There is absolutely no reason your boyfriend has to coach his ex, except as a means for her to tug the string. She knows it, your jealousy mechanism knows it, everyone reading your letter knows it, and so what are the chances your boyfriend doesn’t know it?

Please operate on the assumption that he consents to remain strung, and point this out to him, gently. As in: “I think we both realize your ex has plenty of places she can go with her problems, and that her choosing you is a form of ma­nipu­la­tion — an effective one at that, since you’re complying.”

Then you need to listen very carefully to the way he responds to this, since you’re presenting him with a clear choice: your truth, or her fiction. If he gets defensive or angry or tries to turn it on you, then please don’t lie to yourself that he has your back, on this or much else.

Write to Carolyn Hax, Style, 1150 15th St. NW, Washington, D.C. 20071, or tellme@washpost.com. Subscribe at www.facebook.com/carolynhax.