Stewart, 19, and Fanning, 16, had to share a kiss during the film, which is about the 1970s rock group, with the Twilight star playing Joan Jett and the I Am Sam star playing her bandmate Cherie Currie.
“She was 15, and I wasn't allowed to grope her. I'm actually not kidding, there are major restrictions that I don't remember (from) when I was younger," the Daily Star quoted Stewart as saying. “I don't want to give anything away. It's a really passionate, hardcore scene," she added.