How often does dad go out to the shed? how ventillated is the shed? I grew outdoors under watchful eyes as well, thing is i grew up on a 4000 acre dairy farm that was dotted with swamp holes. I built an encloser with littery branches and tarps and made a dry hut, completely removable before deer season which was always my biggest problem. Just take some rope between 2 trees and drape your tarp over it making a tent, make sure the open parts of your tent are facing in the direction the breeze normally blows, (east and west most likely) inside the tent string across more rope and pin your cola's to that, a week or 2 with good warm daylight temps and breezy weather your bud is dry. A few problems i ran into were more animal related then anything else, the damn deer like to munch on buds, maybe the smell attracted them i'm not sure. I used a deer repellant the next year on my tarp and had no problems again. Not recommending this method, just saying it worked for me in my teen years, cant hurt to try. Next time you plant just plan out the entire grow and harvest before hand, less panic and stress.
