<human>: Can you condense the text into three sentences or less?

She just told me on Sunday. I kept pushing her because she wouldn't talk to me about boys or anything like that, while I have always told her everything. She insisted she just wasn't interested at all.

She finally broke down when I got upset on Sunday and told me that our little brother had snuck into her room three years ago around new years and touched her inappropriately. Now she just doesn't want to be around guys at all. It broke my heart and made me infuriated.

I was going to kill him! I drove to where they live with my dad. I screamed at him, and my sister finally told our dad. I threatened to kill him if he ever touched her again. He claimed he had no idea what we were talking about. He claimed my sister was lying.

We all know she's not. She doesn't lie. She's in love with God Almighty and she would never hurt her brother. He's a super reclusive, bitchy, mean, and selfish teen.

So she's afraid to be there now. My brother thought that no one would ever find out.

How do I treat him?

Why the fuck did he do it?
<bot>: My little brother molested my sister three years ago, whole family just found out. I don't know how to feel or what to say.