I received spam on my seldom-used hotmail.com account with the subject line "Make Your Love Life R Rated". Here's a paragraph from the official guidelines for achieving an R rating from the MPAA:

An R-rated film may include hard language, or tough violence, or nudity within sensual scenes, or drug abuse or other elements, or a combination of some of the above, so that parents are counseled, in advance, to take this advisory rating very seriously. Parents must find out more about an R-rated movie before they allow their teenagers to view it.

Hmmm, hard language, tough violence, drug abuse, teenagers watching with their parents... that's not exactly what I strive for in my love life. "Nudity within sensual scenes" is nice, though.