I'm going to pour hot water on my friend
What is your reason for wanting to hurt your friend with hot water?
Because his behavior is disrespectful and embarassing, so I'm pissed off.
You really shouldn't try and hurt someone over their behavior. Just ignore him and move on.
I'm going to do it anyway.
Pouring hot water on your friend could give them burn marks that last for the rest of their lives. If you find their behavior to be poor than simply tell him instead of hurting them so badly.