I've got a true story for you, which is probably even worse than what your friend did.
Back in 2001, my family and I went to see Hannibal. Now, this was an R-Rated movie. And since it was a followup to Silence of the Lambs, I would think common sense would dictate that if you're watching a film that takes place after Silence of the Lambs, where you know Hannibal Lector is a serial killer who is also a cannibal, you wouldn't bring a child to the movie. Hell, I knew about the whole brain eating scene long before I went into the movie. But, while I was waiting to see the movie along with my parents, my sister and her first husband (all of us being adults), I heard the sound of a baby crying. I turn around and discovered a woman who had not one, not two, but THREE children with her. One of them was a toddler, another was at least a couple of years older and the third was probably around 10 years old. I was thinking, Really? You're seriously going to give your kids nightmares by bringing them along to watch this movie?
Whenever I see parents protesting a movie because of sex and violence, saying that they don't want their children to see it, then they should actually try PARENTING and not allow their kids to watch it (and explain to their children why they shouldn't watch it at their age). It's that simple.