My ex and I have a 13-year-old daughter. We never married. After we broke up nine years ago (in part because of his drinking), he left the country. I never applied for sole custody. We agreed our daughter would live with me, and he never paid for anything. He moved back recently and has been having dinner with her once a week. She’s getting used to having him in her life. The issue: Twice, he has turned up drunk. Most recently, he arrived very late — without responding to her many texts — and was sick in front of her. When I asked him to leave, we argued, and that upset my daughter a lot. (He denies he has a drinking problem; often, he denies he’s been drinking at all.) How can I help my daughter navigate this relationship?

MOM

I share your concern for your daughter. It is really important that she not ride in a car with a driver who has been drinking, or be left alone with someone who is too impaired to care for her. Start drumming that into her head now! And it is unfair to ask her — at 13 — to police adult behavior. (No “call me if he seems odd.”) She is too young for that, and it may be hard for her to rat out her father. Tell your ex that his visits must take place in your home.

Now, in many states, when an unmarried woman gives birth, she automatically becomes the sole guardian of the child until a court rules otherwise. Confirm the laws in your state. Perhaps no further action is required of you, but if it is, petition to become your daughter’s sole legal guardian now to ensure the primacy of your decisions.

The hardest part of this story may be your ex’s dishonesty about his drinking. It makes him an unreliable parent — which may be upsetting for your daughter and prevents you from trusting him. Encourage her to talk about this or, better yet, find her a teen chapter of Al-Anon in your area. If she is going to have a problem drinker in her life, give her the tools to handle it.

When Cutting a Guest List, Don’t Use a Scalpel

My fiancée and I are planning our wedding. (It’s my second marriage, her first.) We’ve made an initial guest list of 60 friends and relatives. We want an intimate gathering that includes all the people who are important to us. Our question: Can we eliminate plus ones when we are friends with only half of a couple (whether married or in relationships)?

GROOM-TO-BE

I could see getting away with a plan that breaks with tradition and eliminates plus ones with whom you are not close if your guest list topped out at a dozen. People would get that it’s a very small, personalized guest list — though I bet you would still upset some of the excluded spouses and significant others. You aren’t saying that you don’t know them, only that they don’t rate. (Ouch!)

But a party of 60 is hardly intimate, even if it’s smaller than many in the wedding-industrial complex. It’s too many people, I think, to let some guests bring partners and to refuse others. Your guests will compare notes, and their feelings may be hurt. Still, it’s your wedding: You can invite whomever you like. But I’d hate for a surgical guest list to outshine your joyful day.

The Other Woman in the Group Chat

My husband and I have been together for 11 years. He is very close with his friends and part of several large group-text chains. One of the threads includes a woman with whom he hooked up a few times long before we met. They never dated or anything. Still, it bothers me that I have to hear from her on these chats. Am I being unreasonable?

WIFE

If I understand you correctly, you are not mistrustful of your husband or suspicious of his friend. And wisely, I think, you are not asking him to leave a chat of friends simply because he hooked up with one of them long before you met.

That leaves three options for handling your feelings: Leave the chat. (They are your husband’s friends, you say.) Mute the woman, if you prefer to remain. Or learn to put up with mild annoyance like everyone else in the world.

A Case of Buzzer’s Remorse

After years of struggling with thinning hair and a receding hairline, I decided to shave my head clean. I thought it would give me a boost of self-confidence. As soon as the barber began shaving me, though, I regretted my decision. I’ve received positive feedback on my bald look, but I fear it’s too drastic. So, I’ve been wearing hats. Should I grow out my hair or stick with my new look?

YOUNG MAN

Take it easy on yourself! Nearly everyone is self-conscious about something, and feeling ambivalent after a big change is natural. I have no idea how you should style your hair. But I asked my excellent barber, who told me your impulse to go short was wise, but you may have been overzealous in cutting it all off. Let your hair grow back to half an inch in length. That will draw less attention and avoid looking extreme.

For help with your awkward situation, send a question to SocialQ@nytimes.com, to Philip Galanes on Facebook or @SocialQPhilip on Twitter.