Apparently, back in the '70s, during the filming of the Bertolucci movie, 1900, Deniro was required to be filmed with full-frontal boner action. (Guess which movie just shot to the top of my Netflix queue?)
Sadly for those of us with prurient minds, it wasn't a method cure, so there wasn't any hot man-on-man action. But instead, according to the Guardian:
His secret recipe, Depardieu explained, involved a combination of water and Tiger Balm, a Chinese heat rub. It was this concoction, he added, that ensured De Niro was able to maintain an erection throughout a scene that demanded full-frontal nudity. The two men have apparently been firm friends ever since.
Get itfirm friends! Love those cheeky Brits!
While Depardieu claims this painful-sounding mixture worked on his friend's knob, I have to wonder about the pain aspect. I mean, Tiger Balm kind of tingles when you rub it on a sore shoulderI can't imagine it'd be very pleasant massaged into your Johnson. And imagine being on the receiving end of such scorched wood. Ouch.