Anyone else notice the new "PG-rated" sex scene trend in movies?

[toddly6666]

Has anyone else noticed that one of the best sex scenes in movies today is when the actress (dressed just in lingerie) just goes on all fours with her butt facing the camera? For example, Mary Elizabeth Winstead does it in Scott Pilgrim. Amy Adams does it in The Fighter. Amber Valletta does it in Gamer. Natalie Portman does it in Black Swan. It's basically a PG-rated scene but it's such a money shot. It's genius. I think I prefer this over any typical cliched nude sex scene in an R-rated film. It's about time filmmakers are now learning from the hyptnotizing power of the butt (remember Catherine Zeta Jones' butt shot in Entrapment, which was the only reason people went to see the film?).

The curvage of the butt when the actress is on all fours is what makes it a money shot. There have been many scenes in the movie where the actress is standing with her back facing the audience, removes her clothes, and all you see is her tush, but it's not the same when the girl is on all fours. The butt curvature and arch of the back is what determines a hotter scene. There's a science to it!

Can anyone think of any other movies with this type of "on-all-fours" butt scene while the actress is staying clothed?