While she's awake!

Two Words: Dutch Oven.

EDIT: For those who don't know what that is... see here: http://www.urbandictionary.com/defin...m=dutch%20oven

Blowing hard *** wind under the covers several times and building up stench while your old lady is brushing her teeth and getting ready for bed, then when she gets into bed, pull the covers over her head and yell "Dutch Oven" and let her enjoy the stench of your *** gas for at least 30 seconds. (definition from urbandictionary.com)