I want them to be embarrassed by the prank, and never know it was me.
I got an idea from my brother and thought that I should just share some
gummy bears with them. But the resulting literal stuff storm and fast acting laxatives might be too easy to single me out.
They are both greedy gluttons and would eat most sweets that anyone would be willing to share with them.
Any other ideas? I shall make this a working poll once I have some other ideas in.