Hiding Pumping?

Ally
How do I hide pumping? I'm going to visit my MIL and BIL this weekend and we will be camping. We will all be sharing the same tent. I definitely need to pump so how do I do it discreetly? I have a battery pack but it's still a pretty loud pump and manual ones are a pain. During the day I think I can manage but at night everyone will be in there. I'm not comfortable enough to just do it, covered or not. Help!!!!