My Sister Owes Me a Lot of Money. How Do I Get Her to Pay?

My sister separated from her husband and moved across the country. Her teenage son did not want to go with her or live with his father, so she asked me to convert an unused floor of my house into a place for him to stay. I explained that I couldn’t afford to do that. So, she agreed to reimburse me for the renovations, which cost $10,000. I charged the full amount to my credit cards, and her son moved in. Now, my sister refuses to repay me — claiming she never made the agreement! She even got our elderly father involved and called me a liar. I am broke from the pandemic and need the money. She is wealthy. What can I do?

SISTER

Let’s put to one side your underlying issues with your sister. We’re unlikely to fix them here. And it seems doubtful to me that further discussion with her will resolve the renovation conflict. The real issue here is this: You spent money you don’t have for your nephew’s, and your sister’s, benefit.

As for her claim that you’re lying: Is there any chance you have proof, in your emails, text messages and other writings, of the deal your sister agreed to? If not, let this be a lesson: Material agreements should be put in writing — even those with immediate family members!

Go to your sister’s ex and your father and tell them you spent $10,000, at your sister’s request, on a bedroom suite for your nephew and that you desperately need repayment. Maybe they will pony up. If not, notify your sister and her ex that their son will be evicted immediately unless you are repaid in full. I don’t see an easy solution to your family problems, but a lodger may help with your money troubles.

The Ragers Next Door

I live with my family in a small town that includes many people with weekend homes. The weekenders tend to use their places mostly in the summer. We have one right next door, and I thought we had a good relationship. But recently, he began listing his house on Airbnb as a great place for parties. We’ve had a succession of weekend renters next door, giving loud parties that often last until 2 or 3 in the morning and keep us (and our children) awake. Our town has no ordinance preventing short-term rentals, and I don’t like calling the police every weekend about the noise. What would you do?

HELENA

The saddest thing (to me) about innovations like Airbnb is how often they destroy our belief that our neighbors care about us. (Or that they care about us only until someone is willing to pay them a few hundred bucks.) Then there’s the noise!

Call your neighbor and explain calmly what his Airbnb renters are putting your family through. Ask him to stop it, or at least to edit his listing to cater to quieter tenants. I know it seems unlikely to you, but he may not have given much thought to what his new income stream is costing others.

I get that it’s no fun to call the police about noisy parties. But I don’t see an alternative here unless you’re willing to walk next door every weekend to ask strangers (who probably care little about your quality of life) to turn down their music.

No Vaccine? No Invite.

I have an extra ticket to an outdoor concert, and I invited a friend who I assumed was vaccinated against Covid-19. He recently told me that he’s not. Even though we will be outdoors, I don’t feel comfortable sitting next to someone who is unvaccinated for three hours. How can I politely disinvite him?

ANONYMOUS

Be direct: “Even though the concert is outdoors, I don’t feel safe sitting next to you for such a long stretch. I don’t want to risk a breakthrough infection. I hope you’ll understand that I am going to invite someone else to come with me.”

Remember, though, you know nothing about the person who will be sitting on the other side of you for several hours. He or she may be unvaccinated too! This is one of the worst knock-on effects of irrational vaccine hesitancy: It is chilling the resumption of normal activities that would be safer for everyone if people (who are medically able) simply got themselves vaccinated.

How to Be a Good Guest

I am tired of going to birthday parties where the host has requested “no gifts, please,” just to be the only person who doesn’t bring a gift. How do you handle this?

MICHELE

Simple: I don’t bring gifts! And neither should you. If hosts are willing to flout the old-time etiquette taboo of mentioning gifts on invitations, the least we can do, as guests, is to respect their wishes.

Try not to compare your choice to what other people are doing. Comparison, as the wise saying goes, is the thief of joy. (It is also responsible for millions of last-minute purchases of undistinguished wine and smelly candles.)

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