Okay, so I (19F) feel like I might be the asshole, but I need some outside perspective because my family is seriously blowing up over this.

For context, I live at home while going to college part-time and working. My older sister, “Emily” (26F), has a 6-year-old daughter, “Lily.” I love Lily, she’s great, but Emily has a habit of dumping her on me last-minute whenever she wants a break. This has been happening for years now, and no one in the family really questions it because, you know, “family helps family.”

So, a few days ago, Emily told me she couldn’t take Lily trick-or-treating this year because she and her boyfriend were going to some adult Halloween party. She just assumed I’d do it. I had already made plans with my friends to go out to a haunted house and watch horror movies, something we’ve been planning for weeks. I told her no, that she should either take her daughter or figure something else out because I wasn’t available.

Well, Emily freaked out, saying I was being selfish and that Lily would be heartbroken if she didn’t go. My mom backed her up, saying I should “step up as an aunt” because Lily looks up to me. I tried explaining that I’m not a built-in babysitter and that I already had plans, but now my whole family is treating me like I’m some kind of monster for prioritizing my own life over my niece’s Halloween.

I feel guilty because I know Lily is excited about it, but I don’t think it’s fair that I’m expected to drop everything every time my sister needs a break.

So, AITA for refusing to take her trick-or-treating, or am I really being selfish like my family says?

UPDATE —- I’ve told my sister that i’m not doing and she shouldn’t expect me to drop my plans for her like i always do and how she shouldn’t have been pushing that on me in the first place and how wrong it is . We’ve all had a sit down with my mom and i told her the same thing and that i’m 19 years old i pay rent here and go to school im an adult and it’s finally time to focus on me we got into a huge argument of course lol they just were bickering about how im apart of this family and shouldn’t feel “pushed “ to help out .. so i’m gonna give it a couple hours maybe a few more comments and give it another go , THANK YOU TO LITERALLY EVERYONE FOR BEING SO SUPPORTIVE i knew i wasn’t over reacting it’s just what i’ve been dealing with for so long it’s felt normal thank you all for opening my eyes to me getting totally pushed around and taken advantage of ! i will update again !!