I 18M come from a large family and I have several little cousins that I regularly look after on Sundays during our weekly family gatherings that we have at my Great Grandmothers. One kid is particular is 7 years old turning 8 in March and has had a strong addiction to fortnite since he was crawling, which has almost definitely impacted how he behaves, he continuously convinces other kids in the family to misbehave in ways such as messing with and wasting water, trying to wet everyone, using vulgar language both verbal and body, such as saying fuck off or fuck you this or that person, pointing the middle finger and just all out being little shits, and since I am usually the one looking after them, they take it all out on me.

I warn them again and again and again and again before going to their parents, and even when they tell them to stop and after they discipline them, they keep going, just recently they were using the garden hose to wet people, wet the playground equipment which is like a decade old and is dangerous when wet, or just wasting it doing some other stuff and they got me from head to toe, swore, flipped the bird and tried to wack me in the balls on several occasions. I was at my brink and ready to discipline the lot and get up them big time but I didn't want to potentially face backlash over punishing kids that weren't mine but it seems even when their own parents try, they refuse to listen, the 7 year old has already even been suspended from school for the bs he pulls on other kids.

So AITA or would this be justified.