Sister drama

I'm babysitting my sister's son for the weekend while she and our mom go on a trip. I asked her how long he's been lying and she turned it on me and said that her kid lying is my fault. I got out of the shower and he said, without me saying anything, that the scissors just magically disappeared and that he didn't touch them. I put him in time out for 5 minutes for lying. The scissors were under the couch cushion where he was sitting.

She told me that he doesn't lie, he just evasively answers questions when he thinks he's in trouble and that I shouldn't expect so much out of a five year old. I didn't even ask him anything. He defensively lied before he was even asked a question.

She also told me that I've done nothing but feed him full of junk food. I did have pizza yesterday but he's had good food today. My sister is 100 pounds heavier than I am and she criticizes my food intake all the time. She had a heart attack and gained weight when she supposedly doesn't eat meat or greasy food.

She just pissed me off.