AITA for Kicking a 6 Year old off my switch account

A couple of months ago my Mum bought a Nintendo Switch to play at her place. To be nice I logged my account into her switch so she can play the games I have purchased. I buy all of my games online because I don’t have room to keep physical copies of games, this means she has a huge selection of games to choose from.

Tonight, My Partner(26F) and I(25M) are sitting at home playing Mario Kart 8 on my Nintendo Switch. My existing Joycons had really bad thumbstick drift so I decided to buy a new pair this morning. All we’ve been wanting to do since we got home is jump on and play with my new controllers.

We have been playing for a while when all of a sudden an error message comes up on my screen reading “Someone else is playing on your switch online account so you cannot access this content. Please contact Nintendo support if this is not you.” Naturally I thought to myself, oh my mum must be trying to play on her switch, I’ll just text her to hop off since my partner and I have been looking forward to playing all night. Then she sent me a text saying that her and her friend are having a few drinks and her friends 6 year old child wanted to play. I said to her that my partner and I have been looking forward to playing with my switch all day so if she could hop off while we were playing.

She then immediately started an argument, making me feel bad for kicking the kid off of the switch. They wanted to distract him while they had their fun drinking. I explained to my mum that there was plenty of other ways to distract the child like putting on a movie. My partner and I really wanted to play and the child kept kicking us off the switch account.

I then jumped into my account and logged my account off their switch so that I could play my games in peace. Since I logged them out ,there was nothing they could play as to log back into my switch they would have to have my phone for 2 factor identification.

This started world war 3, with my mums neighbour even getting involved by sending a message asking me to hop off so that her kid could be distracted while they have their fun. Am I an asshole for kicking the kid off my switch account that I payed for so my partner and I could play them?