I (25f) moved in with my boyfriend (27m) a couple of months ago, and for the most part, things have been great. The only issue that’s come up is with his younger sister (18f), who also lives with us.

She’s been living with him for about a year now while she goes to school. She commutes to campus instead of living in the dorms because of some chronic health issues, which she and my boyfriend claim make dorm life too difficult. They've never told me any specific condition, though, and from what I can tell, she seems fine most of the time. I’m not saying she’s faking, but I do think she might be exaggerating how bad it really is.

Right now, she’s not paying rent, but she’s said she plans to get a part-time job this summer and start contributing financially. That’s fine, and when I moved in, I didn’t expect her to be paying rent right away. But I did expect that she would help out with chores, especially since I work full-time and she’s home more than either of us.

To be fair, she was really helpful when I first moved in. My boyfriend even told me that she’s super responsible and keeps the place running. I saw that too, she was good about dishes, trash, and tidying up. But for the last couple of weeks, she’s been doing the bare minimum and nothing else. When I asked her about it, she said her chronic condition flares up when the weather changes, especially with all the rain we’ve been having lately, and that it’s been causing her a lot of pain.

I just don’t really understand how the weather could make someone physically unable to do basic things like vacuuming or wiping counters. I didn’t say that to her directly, but I’ve been getting more and more frustrated.

Then, on Friday, I came home from work and saw that once again only the dishes were done. I went to her room to check in and found her at her desk, watching videos. I asked why nothing else had been done, and she started crying. She said that after doing the dishes, she got lightheaded and exhausted and needed to take a break. She also said she was working on a school assignment at the same time.

I didn’t think that was a good enough excuse. I told her that she’d done those chores before and can do them again and that she’s lucky to be living rent-free. I said it’s not fair to expect other people to clean up after her. She cried more and told me to get out of her room.

After that, she called my boyfriend and told him everything. He immediately took her side and got really upset with me. He said what I said was hurtful and degrading and that his sister already feels bad that she can’t do more. Apparently, she’s really self-conscious about it and is doing her best, and my comments just made her feel worse. I tried to explain that I wasn’t trying to be mean; I was just frustrated and wanted her to take some responsibility.

Over the weekend, my boyfriend has been really distant with me. I said I was sorry, but he said that it wasn't him who I owed an apology, and until I give his sister a proper apology, and she accepts it, that he wouldn't forgive me. I understand that he wants to protect his sister, but I don’t think I was unreasonable. I didn’t yell at her, I didn’t insult her; I just pointed out that she has responsibilities like the rest of us.