How to Have Sex in the Shower
Clear the shelves. You'll need the ledge where you normally store your shampoos, conditioners, and three different types of shower gels to keep your balance.
Grab the lube. Water might be, well, wet, but it can actually make your skin feel like sandpaper when doing the deed.
Pick a position with the lowest risk of slippage. Standing doggy-style (you bent over, him behind) is a safe shower standby. Avoid anything that requires him picking you up -- unless you want to explain to the ER doctor how you fractured your tailbone.