Q. I have been married to my husband for four years. My husband’s ex has an annoying habit of texting him on his birthday every year. They are flirty texts, not just “Happy birthday” and I find them way out of line.

My husband and his ex have been divorced for more than 10 years and the kids are in college, so they have very few co-parenting conversations, yet she reaches out every year with a cutesy little message, complete with heart emojis and flashing GIFs. It is our well-founded belief that she does this just to rub me the wrong way. Should we tell her to stop or allow it to continue to keep the peace?

A. Should we tell her to stop? No! Should your husband tell her to stop? Absolutely!

The ex-etiquette rule of thumb for this kind of situation is that the person to whom the perpetrator (your husband’s ex) is related is the person to speak up. That means if it was your father who was out of line, it would be you to talk to him. If it was your sister or friend who was out of line, again, it would be your responsibility. This is your husband’s ex so he should be the one to address the situation.

Not telling her to stop sends her mixed messages. Basically, he’s telling her it’s OK to be inappropriate, and she probably thinks their little joke is just between them. Without a reason to stop, she will continue the behavior. Even if she knows in her heart it’s tacky, his not taking a stand is telling her it’s fine.

I’m of the opinion that “Happy birthday” is an appropriate text if the communication in the past year backs up the behavior.

But only IF — and that’s capital IF — the current partner is not offended by the behavior and there is no behavior on either ex’s part that can be misconstrued to be something else — like heart emojis. That is extremely disrespectful to you, and very bad ex-etiquette. Your husband should have taken a stand years ago.

I suggest he take care of this as soon as possible. If he waits for next year, you will have yet another year of irritation about all this.

Boundary set. That’s good ex-etiquette.

Dr. Jann Blackstone is a child custody mediator and the author of “The Bonus Family Handbook.” /Tribune News Service