What does “Сейчас всё брошу и побегу!” mean?
When person A sarcastically responds «Сейчас всё брошу и побегу!» to B's request, it means that
- A has negative emotions towards either B and/or B's request; A could be annoyed, feel underappreciated or disrespected.
- A implies that he/she has no intention to fulfill B's request, commonly on the ground of being busy or having better things to do at the moment.
It is rather unlikely, but still possible that there is no meaning-reversing sarcasm in that phrase. E.g. a boss can say «Так, бросили всё и бегoм на медосмотр!»
We know it's not the case as A mentioned that the movie is about to start, but if it were A would mean that
- A is going to stop doing anything else and hurry up to work on B's request right now.
“Сейчас всё брошу и побегу!” is literally translated as "I will throw everything and run!" but I suppose that really it means something else
Translation (as usual) heavily depends on the context and translator's goals. As a translator you have to prioritize multiple things like
- making sure your audience understands the meaning to a good extent
- preserving original phrasing, idioms, and cultural references
- preserving multiple meanings when relevant
- matching the level of sarcasm and irony
- matching the register
- matching usage frequency of words and expressions
- matching the use of jargon words
- etc etc
The choice would be influenced by the expected reader audience familiarity with expressions, understanding the original culture and cross-cultural differences. E.g. if you need to simplify to the maximum, a translation can indeed be
You're kidding, right?
Though this is a bit too far from the original: the reverse translation will turn «Сейчас всё брошу и побегу!» into «Ты, конечно же, шутишь?».
One can try to preserve the original wording and pick closer idioms. However и побегу part implies too much and has a slim chance to survive the translation undamaged without becoming too vague and/or clumsy. I'd probably go with something along these options
Right, like I gonna drop everything and get your coffee!
Oi! As if I gonna drop everything and fetch that!
Oh, should I just drop everything and do as you say?!