Hi Eldad, do you mind interpreting this sentence in English or in other Hebrew equivalents? I got lost in guesses))

תקבל על הראש!
or:
You will be seriously scolded!

but what are FATHERS doing there? reminded me of the famous Russian показать "Кузькину мать".

I'm not familiar with the expression you mentioned in Russian. ☺
In Hebrew, this is the expression. I have known it for ages; sorry, at the moment, I cannot explain where it comes from, but I'll try to explain later, if I manage to remember.

I googled, but could not spot anything informative. Thanks anyway!

Since you do have some Russian knowledge, you might check - I guess you will enjoy (esp. the use by Khrushchyov). There is one more, получишь по первое число (kind of תקבל מקות כמה שמגיע לך, כמו שצריך )

(I brought the Russian examples just because they are also hardly explainable for most native speakers, but still broadly used)

תקבל מכות ☺
Thanks a lot for the examples in Russian!

תודה גם לך!

:)