And, here's a sick practical joke I do on guests...you're wife will really freak out.
During the day when no one is home, put some peanut butter outside. At night, find a reason to go outside, "I forgot to turn off hose, check car, etc." Go outside & get a dab of peanut butter (keep it concealed in your hand. Return inside to watch your favorite show. When no one is watching, smear a big lump of it on the bottom of your shoe. Sit with your foot with the peanut butter on top of the knee. (half indian style). Someone will notice the "brown stuff" on the bottom of your shoe. "Did you step in something?" Act suprised, look at it, then take a scoop of it with your finger and taste it.