Door latch warning for temporary excursion

About three times a week, I like to leave my home and go for a quick jog around the area. It clears the mind, strengthens the body and my scant little loin cloth is a big hit with the ladies. The thing is... that's pretty much all I'm wearing. There are no pockets for keys or garage door openers so I usually end up leaving the front door unlocked behind me during this brief excursion.

If there's ever a chance that a housemate awakes during this time and decides to stumble to the front door (in their usual hungover state) they just might summon the temporary lucidity to twist the latch back to the locked state (and then head to fridge for another beer and pass out a few moments later as I'm trying to climb in through the window or something). Pfft. Housemates.

SO... I made this doo-hickey. Just put it on the latch in the unlocked state on your way out and your fellow heroin-infused home dwellers won't even touch it. It's shaped a bit like a stop sign so they don't even ne