When little kids are in inappropriate movies, do they let the kids see them?

I was watching little miss sunshine this morning and it had abigail breslin when she was about 7 or 8, but they were dropping f bombs and talking about sex, heroine, etc. around her. Do you think that when little kids are in inappropriate movies the parents let the kids see themselves in the movies? I don't think they do but I wanted to get some other peoples opinions.