The phrase "watching the faucets run" comes from a joke about Till Lindemann between fans. The joke was a badly drawn picture of Till Lindemann, watching his bathroom faucets run because it reminded him of his days as Olympic swimmer. Originally as a poke at the lead singer because his stage persona comes off as very serious and dark, it now can refer to any man.
Asking "Does he watch the faucets run?" would mean that you are asking the person about whomever man your are talking about if he carries similar traits as Till Lindemann and/or if the person being asked the question finds so said man attractive.
For a man to be qualified as a faucet watcher, he must be: Tall, barrel-chested or well built, beautiful, and looks like a complete bad ass.
"Austen Loves watching the faucets run, he would turn a lesbian straight!"