Should I steal my friend's cat?
That does not sound nice. How do you think he'd feel if you stole his cat?
I'm going to talk to my friend about it and see how he reacts
You shouldn't steal things from your friends. They'll get angry and feel as if you betrayed them. They'll probably end your friendship if you aren't remorseful and return what you took.
Why can't I steal his shit, he's been stealing my stuff since junior high and we are still friends.
And he shouldn't have but if you had a problem with him taking your things then you should have spoken to him about. Instead of using that as an excuse to take his cat. Also a cat is more valuable than things.