AITA for exploiting my grandma’s dementia so I could watch tv?

So about a year ago my aunt and my grandma moved in with us because my grandma has dementia and my aunt needed some extra help taking care of her. It’s been pretty difficult just because it’s hard to take care of someone who’s so mentally gone, but to be fair my aunt does the majority of the caretaking and I usually just help out when I can.

Well yesterday my mom and my aunt had a church thing they needed to go too and my dad is out of town so they asked if I’d be fine watching grandma on my own. I told them that was fine since it was only gonna be for a few hours and she was already dressed and all that. I just would need to give her lunch and stay with her to make sure she was alright.

They left and about an hour later I helped her sit in her chair in the living room and gave her her lunch. I’ve been rewatching Star Wars: The Clone Wars, so I decided to put on an episode while we ate. After she finished her lunch she said she wanted to play mancala. I asked if we could finish the episode first and she said okay.

She always wants to play mancala and I always have to pretend like it’s fun but it’s seriously the most boring game in the world. I like spending time with her but I can’t stand mancala.

About 5 minutes after she asked the first time, she brought it up again but she was saying it as if it was the first time she was asking. I never say “you already asked that” or anything like that when she repeats herself because I don’t want to embarrass her, so I usually just respond as if it really is the first time that she said or asked something. So I just asked her again if we could finish the episode first, and she said yes again.

A few minutes later the episode ended, but I really didn’t want to play mancala so I just pressed play on another episode to see if she’d say anything. She didn’t say anything so we kept watching. Every 5-15 minutes she would ask to play mancala and so I would just ask if we could finish the episode first and she’d say yes. I figured if I play with her eventually then she’ll only remember the time I said yes and forget about the first 50 times that she said she wanted to play.

I didn’t realize how much time had passed though and my mom and my aunt came home before we ever played. My grandma asked my aunt if she wanted to play mancala with her, and I knew they’d be upset if they knew I just watched clone wars the whole time, so I said “grandma you wanna play mancala again? Okay we can play again”

My mom said I don’t have to play again cause she knows I don’t like it so I just went back to watching clone wars. I felt like everything worked out but I sorta feel wrong for lying and I feel like I kinda took advantage of the fact that my grandma has dementia. AITA?