And this: wasn't?
Nope, as it actually made sense if you could comprehend logic.
He was making a statement, and I was agreeing with him. I could also say I'm "with him" in 2 different meanings as in
1. I am physically by him
or
2. I am on the same level as he is with an agreement.
I used number 2 so therefore it made a lot of sense. Throwing in the word "stupid" was just added fun.