Good April fools prank for a sibling?

Have a funnel and a penny.

Put the funnel in your pants and the penny on your nose.

Lean your head down and the penny should go in to the funnel.

Challenge you sibling to do the same thing - i.e. put the funnel in their pants and drop a penny in it from their nose.

When your sibling has their head tilted back have a glass of water (best if it's ice water) and pour the water into the funnel - and then run as fast as you can