Can I put Sims 3 on a flash drive? If so, what size, and how?

I would love to get the Sims 3. However, my parents always say no to sims games due to the amount of space that they take up on the computer. I have wanted one since I was eight, so, for my 16 bd Im asking for the game, yet again. I think I could convince them if I could put it on a flash drive. Any tips would be very welcome and appreciated.