Is she free to date other men?

I read from several sources that while her husband is loyal and faithful to her , she is fee to date/have sex with other guys, is this true? And if so is it more her idea than his? http://www.answers.com/article/1213217/9-celebs-you-never-knew-were-in -open-relationships?param4=tb-us-de-enter#slide=2

Boston and Philly love to slander us, but they don t have as many fans as us