to amuse yourself at someone's expense = tirar onda, tirar um barato, tirar com a cara de alguém
Frequently, when I return home from work, I find my wife drinking with some of her friends. I don’t mind if she drinks, that is ok with me. But often my wife and her friends become very drunk and start insulting me and amusing themselves at my expense.
hold a person up to ridicule
are you fuckin' with me? - tá me tirando? / tá tirando uma com a minha cara?
don't f*ck with me! - não brinca comigo! / não vacila!
scoff - to laugh or say things to show that you think someone or something is stupid or deserves no respect
Example: It's easy to scoff when you haven't tried it yourself.