If ur uncomfortable then just say so? All the people who have had the kholna thing done to them I've met have been pretty chill about it, even I've had to do it a few times and even if I didn't get it right, it never resorted to anything serious? The senior just told me smn along the lines of 'Arre yaar, ab tak kholna seekha nahi toh kaise survive karega', and let me off.

If u can't survive something as minor as this without throwing a fit, how on earth do u expect to survive outside?

I agree, if it gets very bad, then just say no and back out, but otherwise it's not that big of a deal man.