In Hungary, when someone tells you something negatively unexpected, Hungarians might say "Mi az anyád?", which, if we translate it literally into English, means 'What is your mother?' It's basically a milder or more playful way of expressing surprise and frustration —similar to saying "you son of a b..." but less harsh. Still, I recommend using it only with close friends who are around your age.

Example :

- These 2 bags of milk cost 5000 forints

- What is your mother?