DEAR ABBY: My fiancee of three years, “Ellen,” is wonderful to me and she loves my daughters dearly. However, when it comes to my ex-wife, Ellen can be downright nasty.

I divorced my ex-wife many years ago because she wasn’t good to me, but my kids see her half the time and love her because she’s their mom, and I encourage them to do that. Ellen says nasty things about her in front of my kids, and of course my kids don’t like it and tell me about it. When I confront Ellen about it, she tells me I stick up for my ex more than her and tries to make me feel guilty.

My kids are my world, Abby. I love Ellen, but I refuse to lose my kids because my fiancee can’t control her mouth. I don’t know what to do. If I lose Ellen because of my ex, I’ll be devastated. Do you have any advice for me? — CAN’T WIN IN PENNSYLVANIA

DEAR CAN’T WIN: Try asking Ellen how she would feel if she were in your daughters’ shoes and someone constantly said nasty things about HER mother. I’ll bet she wouldn’t like it one bit.

You say Ellen loves your daughters — yet she persists in doing something she knows is painful for them. That isn’t loving behavior, nor is it kind or sensitive. My advice is to tell Ellen she needs to do some work on quelling her insecurity and hostility because she’s driving your daughters away, and they are your world. And add that if you hear she’s continuing to make nasty comments about their mother, although it pains you, you will miss her.

DEAR ABBY: Every time my girlfriend and I go out somewhere and we run into friends of hers — mainly females — they always make a point of telling me how lucky I am to have her. Mind you, she is gorgeous, and I do feel lucky. But I’m not bad-looking either.

What is a proper response for me to give? It’s beginning to get irritating. — ALSO A GOOD CATCH

DEAR ALSO A GOOD CATCH: The proper response is, “Isn’t she terrific? She’s not only gorgeous, she’s (then list several of her other virtues).” Remember, this is not a competition. The more you build your girlfriend up to her girlfriends, the better YOU will come across. And of course, she should do the same for you whenever the opportunity presents itself.

DEAR ABBY: How come when people ask what kind of sports you do and stuff like that, they always direct it to my brother or my dad? They never ask me — I’m a girl — or my mom. I consider it rude and sexist. I feel I should do something about it, but I’m not sure what. Please help me. — CLAIRE IN SAN FRANCISCO

DEAR CLAIRE: People who do this obviously don’t know your family well, or they would already know the answer to the question. That tells me they are only trying to make polite conversation.

Because it bothers you, I think you should tell your father and brother how it makes you feel. Perhaps the next time they’re asked, they could make a point of mentioning that you’re involved in sports, too, so you can be part of the conversation.

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