I'm writing a short story with a Russian character who is getting a tattoo in an English speaking country. There is a moment where the tattoo will be particularly painful, and she will make some kind of exclamation, kind of like 'Ouch' but stronger, more like 'fuck, that hurts!' The tattooist is actually also Russian, but the main character doesn't know until the tattooist says they don't usually get other Russians in their store.
I've tried to look up a suitable word/phrase for her to say that would sound natural in the situation but is not overly aggressive, but all the options I have found are either too hostile or otherwise does not suit.
The best term I have found is 'охуеть' as it seems to be used when one is (negatively) surprised about something, but I still have my doubts about a Russian speaker using this in front of a stranger (even if they think the stranger cannot understand Russian)
Any help would be appreciated :)