DEAR ABBY: I’m a single mother of a 1-year-old boy, Zack. His father, my ex, has shared custody, but we don’t have a very good co-parenting relationship. Shortly after I gave birth, he left me to be with a woman he had met while I was pregnant, and they are still in a relationship.

She thinks it’s OK to post pictures of Zack on her social media sites. I have a problem with this, not least of all that it is incredibly hurtful to see another woman pretend she is in a “mother” role with my son.

I have confronted my ex about this and although he told me he would talk to her about it, he also told me it is none of my business what happens while Zack is in his care.

Am I right to make this an issue, or do I need to move on and accept that this woman is in my son’s life? — OFFENDED IN SAN JOSE

DEAR OFFENDED: I sympathize with your feelings, but your ex is right. Unless something is happening that’s dangerous to Zack’s welfare, you can’t control what happens when he’s with his father.

I don’t know how serious this new relationship is, but it appears to be a long-lasting one — and whether you approve or not, this woman is in your son’s life in the role of part-time mother. For your sake, you need to accept it because the alternative is to make yourself sick over it. And because it’s hurtful, stop reading her posts.

DEAR ABBY: I married the love of my life eight years ago. He’s a wonderful husband, father and provider. He has just one flaw — his hygiene.

He works long hours and is usually exhausted when he gets home. He showers maybe once a week, and brushes his teeth less often. Sometimes he makes sexual advances, but I’m so turned off by his smell that I just can’t do it.

I have tried asking him to be cleaner. I have even been upfront about what other people have said about his lack of cleanliness. I even tried making shower time “fun,” but a girl can’t do that every night!

I’m becoming so frustrated. I’m a clean person, and I keep hoping one day he’ll adopt my habits, but it doesn’t look like it’s happening soon. Any advice? — HOLDING MY NOSE IN IDAHO

DEAR HOLDING YOUR NOSE: It appears this wonderful husband, father and provider has the personal habits of a goat. If he has enough energy to make advances at the end of a long workday, then he should have enough to take a shower and brush his teeth. Unless you plan to wear a clothespin on your nose during marital relations, you should insist upon it.

DEAR ABBY: I have been invited to a high school graduation for twin girls. One of them has been our baby sitter for almost three years, and we have formed a close relationship with her. We know her sister, but do not have the same relationship with her.

We would like to give our baby sitter more money for graduation, but do not want to offend her sister. What should we do? — CAN’T DECIDE IN OHIO

DEAR CAN’T DECIDE: When you give the girls their graduation cards, enclose a check in each for the same amount of money. Later, privately, you can give your baby sitter something extra as a token of your appreciation. That way, it will be less obvious and may avoid hurt feelings.

Dear Abby is written by Abigail Van Buren, also known as Jeanne Phillips, and was founded by her mother, Pauline Phillips. Write Dear Abby at www.DearAbby.com or P.O. Box 69440, Los Angeles, CA 90069.