As such, I resented how Zack could care less about the other ladies in the film -- Stacy and Bubbles, who are both porn stars in real life and portrayed as blond, dimwitted, red lipstick-leopard-print-coat wearing sluts.  Despite the fact Miri sleeps around as much as he does, and perhaps even as much as the other actresses,  Zack is protective of Miri showing her breasts onscreen, or sleeping with the male porn stars.  (To be fair, Miri doesn't like Zack sleeping with the women in the film, either.) Nevertheless, the film focuses on a triangle between Zack, Miri and one of the actresses, so I perceived that as a message that slutty girls are discardable until a guy likes one of them. 

I've been in their shoes, too, and had to tease out love interest/friend knot; I don't propose to have any better answers than they do.  Still, I  felt disappointed that this story of confusion about sex in 2008 hit so close to home in a f*cked up way.  (Minus that porno-filming part.  Hi, Mom and Dad!)  It's lamentable some of us are so  jaded and confused about sex and intimacy -- and for what reason? 

In any case, don't see Zack and Miri just to prove me right or wrong.  See it for the best cameo ever by Justin Long -- a drunk gay porn star!