AITA for refusing to babysit my sister’s “angel” kids after they destroyed my entire gaming setup?

Last weekend, my sister (32F) asked me (28M) to look after her two kids, ages 6 and 8, for “just a few hours.” I agreed since I work from home and want to support her as a single mom.

That was a big mistake.

She dropped them off without warning me that they were out of control. Within minutes, they found my office. Even after I told them not to touch anything, I came back to find: • My custom PC turned on with drink spilled all over my mechanical keyboard • My dual monitors smeared with what looked like peanut butter • My cat locked inside my 3D printer enclosure • One of them sitting on my Wacom tablet, drawing “poop emojis” in Photoshop

I lost it. I didn’t yell, but I firmly told them to sit on the couch and do nothing until their mom returned. When my sister came back, I calmly explained what happened and showed her photos. She laughed and said, “They’re just kids! Don’t be so uptight.”

I told her she needs to cover the damages, which cost around $800. She responded, “You’re family, not Geek Squad.”

I told her I won’t babysit again until she replaces my gear and teaches them boundaries. Now she’s calling me “childish” and “selfish” for “holding a grudge against kids.”

My parents think I should let it go because “she’s struggling.” But I feel disrespected and taken advantage of.

AITA for refusing to babysit again until she pays for the damage?