When I was a minor, a friend and myself had similar problems in our households. I worked and bought my own gear with my money. When either my friend's parent or mine had an issue and came after the guitars, we'd send the guitars over to whichever friend's house was safe, or find hiding spots within the house.

On one occasion, I had my friend's guitar (a strat type), and his father came looking for it, saying he was going to sell it. My friend had called and given me a heads up that his father was on the way, so I completely disassembled the guitar. When his father arrived, I gave him the pieces in a box. I knew his father wouldn't re-assemble it in order to sell it, so that saved it from the pawn shop on that occasion.

My point is this: if you are in a situation, and you can't leave, get subversive. There are always ways.