"But you have to!"

Today I assisted Dr. Russian and Dr. B.
(Some of the nurses call them the deaf and the mute because Dr. B can't hear very good and Dr. Russian doesn't talk very much.)

So, Dr. B wanted something from Dr. Russian.
He answered super relaxed, unexcited: "Dr. B, I still can't read your mind."
Dr. B screamed at him: "But you have to!!"
Dr. Russian rolled his eyes and continued working..

Actually this is the perfect sentence to win every argument.
"I don't wanna do this and that."
"But you have to!"

"I'm sorry, I am not allowed to let you take 3 months off."
"But you have to!"

"I am not able to get another pair of hands and finish all the work at the same time."
"But you have to!"

Gnihi..