DEAR ABBY: My wife and I have been married for four years. When we got married, we were both monogamous. We wanted kids and a classic nuclear family, and our interests and political beliefs were similar. We had three kids in 15 months and received no help from anyone.

I wasn’t the perfect husband. I sought out other women via online dating sites, though I never cheated. Toward the end of our fourth year of marriage, my wife slept with another man who has been a friend of hers since she was younger. Now, she wants to have an open relationship. She wants to go over to other men’s houses at all hours of the night. If she goes out, she usually doesn’t return until 4 a.m. or later. I have seen texts with other men she calls “sexy,” telling them she’s attracted to them, among other sexual language.

I told my wife I’m not a jealous person, but I’m not polyamorous, and it’s driving me crazy that she refuses to stop. She claims I’m trying to “control” and “isolate” her, and that it’s my job to get over my jealousy. What can I do to reach her? — AT ODDS IN OHIO

DEAR AT ODDS: You have serious decisions to make, among them what is best for your three children and yourself. It isn’t controlling to want a monogamous marriage. If that lifestyle no longer interests your wife, I don’t think she’s going to be willing to change her ways.

Frankly, I am shocked that after parenting three children for four years, she has the energy to stay out all night. Could there be something hormonal going on with her? Postpartum depression? Consult a licensed mental health professional to help you figure out what may be going on. And while you’re at it, talk with an attorney, not only about your options, but also about child custody if necessary.

DEAR ABBY: Our adult daughter, “Amanda,” and our three-year-old granddaughter, “Lucy,” live with us. I watch Lucy while Amanda works. Her commute to work is about 20 minutes. We live in a suburb of a big city, so once in a while traffic causes a delay, but not on most days. Amanda wants to leave for work an hour and a half before she has to be there because she is anxious about getting to work on time. I think leaving 45 minutes before she has to be there is reasonable.

Am I being a jerk if I tell her I’m unwilling to take responsibility for Lucy until 45 minutes before Amanda has to be at work? I’m not trying to be insensitive to my daughter’s anxiety, but I have many responsibilities of my own, and my time is valuable. — BUSY MOM, TOO, IN KENTUCKY

DEAR MOM: Your daughter may be anxious about the traffic because she has had a bad experience or two. Her employer may also be a stickler for being punctual. Talk to Amanda and see if perhaps you can work out a compromise — she leaves for work one hour before work, and you have that extra half hour to yourself.

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 http://www.DearAbby.com or P.O. Box 69440, Los Angeles, CA 90069.