Nobody wants to disappoint or appear unhelpful, but if you never master the art of the negative you’re going to find yourself spending a whole lot of time and energy doing stuff you don’t want to do. And, really, life is too short. Here are some polite ways of saying ‘Not on your nelly!’
Yes, it’s a lie – you wouldn’t love to dog-sit your cousin’s demented Weimarana while she takes a road trip to Nieu Bethesda, but saying this softens the blow. Then, (quickly) think up a viable reason why it won’t work, sticking as close to the truth as possible. If you’re caught off-guard and can’t think of anything, don’t deliver a knee-jerk ‘Erm… okay’ which will be hard to go back on later. Rather, tell her you’ll think about it and get back to her ASAP. This gives you time to find a way of saying ‘No way, José! – gently.