I don't speak Greek; one of my jobs here is to make sure the English is gramatically correct and sounds ok. It sounds like there is a word missing in this translation. Please let me know what you think of my suggestions below. Thanks!
I wonder... "Where do you think you are going like that, you ass?"
or
I wonder... "Where do you think you are going with that, you ass?"
"ass" (κόπανος, ηλίθιος) isn't the word for "σοÏÏγελο". "σοÏÏγελο" is a slang term used to call someone "ridiculous person" (because of the way s/he dresses/behaves)