DEAR ABBY: My two daughters are not speaking to each other. "Amy," the older, claims her sister started it. "Lisa," the younger, claims Amy took Lisa's son out to dinner and never told her. (This happened while he was living with me -- another long story.)

Amy has had us at her house for Christmas for the past seven years. Lisa wants to have Christmas at her home this year. She told her aunt that if I don't go there for Christmas, she will never speak to me again. I have tried hard to get Amy to make up with Lisa. I think Lisa wants things to go back to the way they were. (Amy doesn't know what her sister said to their aunt.)

It feels to me like Lisa is asking me to pick which daughter I love more. How can I handle this without losing a daughter? -- IN THE MIDDLE IN MASSACHUSETTS

DEAR IN THE MIDDLE: Handle this by telling Amy that because you have celebrated Christmas at her home for the last seven years, you will be spending this one with Lisa. And if she gives you an argument, tell her that from now on you will be alternating celebrations with her sister because you do not want to be forced into the position of having to choose one daughter over the other.

DEAR ABBY: I am a 68-year-old man, married for 45 years. I have cheated on my wife for most of them. Am I sorry about it? No.

My wife shut me out of her life 25 years ago. She has her bedroom, and I have mine. Why did I stay with her? We had adopted two babies 30 years ago, and I wanted to give them an education and a good start in life, which is what we did.

How do I treat her? I treat her well, I think. I help her with the housework, keep our home in good condition inside and out, and she has her own car. I take her out for dinner once a week and we go dancing every Saturday night at the club. I'm a moderate drinker and nonsmoker. I bathe four or five times a week. So, tell me, Abby. What's wrong with me? If you decide to print my letter, perhaps I'll have an answer. Thanks, Abby. I enjoy your column very much.

P.S. Would I cheat on my wife if the opportunity presented itself in the future? Darned right I would! -- NO REGRETS

DEAR NO REGRETS: If you are asking me what's wrong with you for staying in your marriage, my answer would be that you did it for three decades for the sake of your children. I would add that since they are now all adults, it may be that you eventually adjusted to the lack of intimacy with your wife, so you substituted women who were available.

However, if you are asking me why your wife shut you out of her life 25 years ago, the only person who can answer that question is her. It may not be too late to ask.

DEAR ABBY: I have a friend I'll call "Whitney" who asks me to pet sit for her on a fairly regular basis. She'll usually ask me a week or less before she is going to be leaving. I love animals (I have several of my own), so I continue to do this for her. But one issue is making it increasingly difficult. Abby, her house is FILTHY.

I have animals, so I know a little dog hair or cat litter is part of the deal. That's not the issue; it's dirt from the humans. There is food residue on counters, stovetops and cabinet doors, clothing and paperwork all over the floors, and a bathroom that clearly hasn't been cleaned in years. I refuse to use the bathroom in her house, and I even sanitize my hands after I leave.

This makes the pet sitting harder, because I know I should spend more time with her cats than just scooping litter and filling dishes, but I simply cannot bring myself to spend any real time in her house. How do I broach this subject with her, or should I? I dread these requests, but I don't want to leave an animal without basic care when she's away. -- RELUCTANT PET SITTER

DEAR SITTER: The time has come to tell Whitney you no longer want to pet sit for her, and when she asks you why, tell her the truth and encourage her to get some cleaning help.

DEAR ABBY: My son's wife (I'll call her "Carla") calls me when they are fighting. The last time, my son went to jail for domestic violence. The cop didn't even talk to me.

Now my son won't talk to me, and I'm no longer allowed to talk to my grandchildren. He says as far as he's concerned, my husband and I are dead. We did nothing but help Carla. It was my son's third domestic violence offense. I always had a great relationship with my grandchildren, but I haven't seen them in more than five months. I miss them very much. Should I stand up to my son, tell him to grow up and let me see my grandchildren, or honor his request and stay out of his life? -- PUNISHED IN MINNESOTA

DEAR PUNISHED: You can't force your son to do anything. Accusing him of being childish will only cause more animosity. Talk to Carla and point out that your son needs psychological help. Carla should take the children and go to a shelter, because without professional help and a desire to change, your son's attacks will escalate and he could seriously injure or kill her one of these days. Carla should contact the National Domestic Violence Hotline for guidance. The toll-free number is 800-799-7233.

DEAR ABBY: I went for a jog the other morning, and when I returned home I discovered I was locked out of my house because the garage door keypad wasn't working. I had left without my cellphone or a key, so I tried to contact my wife through our Ring doorbell. My wife told me she'd phone a friend and my mother to see if they could deliver a key.

In the interim, I fidgeted with the garage door keypad and discovered I could remove the battery. I knocked on the door of a neighbor who'd previously popped their head out and asked to use their cellphone and also asked if there was any chance they had a replacement battery, which they did. My neighbor invited me inside to call my wife and wave off a key delivery.

I later stopped and bought a thank-you card, a replacement battery and $20 in Amazon gift cards with the intention of gifting all three to my neighbor. My wife thinks the gift cards were unnecessary and a "weird" thing to give my neighbor.

The neighbor and their partner are in their late 30s or early 40s, seemingly financially well enough off, and I thought a gift card was a universally accepted gift. I thought it would be a nice gesture without being too over-the-top. Was I too generous? Or is it too forward of an offering? -- SAVED IN THE MIDWEST

DEAR SAVED: Your offering wasn't weird, too generous or over-the-top. The gratitude you were expressing was from your heart and a reflection of how desperate you felt at the time. Your wife should have stayed out of it.

DEAR ABBY: Forty years ago, I had an affair with a married man. When he broke up with me, I didn't think I could live through it, but I had a 2-year-old daughter from another relationship and I had to hold it together. A few years later, I met and married my husband of 35 years.

Three months ago, I received a message on Facebook saying, "If this is who I think it is, how are things?" I know I never should have, but I answered. My former lover lives hundreds of miles from me, but we text almost every day. I am just realizing how narcissistic he is, and I need to end this.

My husband and I have had problems over the years, but we have raised three very successful children and have three beautiful grandkids. It was nice to hear how my ex always loved me and how we are soul mates -- saying everything I wanted to hear. But now that I've been dragged down that rabbit hole, I need to get out and quit falling for his lies. Please help. -- MUDDLED IN MASSACHUSETTS

DEAR MUDDLED: If this emotional fling continues, it will destroy the life you have created with your husband of 35 years. If there are issues in your marriage that made you vulnerable to your old lover, I urge you to deal with them. Please reread the first paragraph of your letter, then GHOST AND BLOCK THIS PERSON. You owe him nothing -- not even a goodbye.