Jenny McCarthy accidentally wore her designer frock backwards at her first Oscars. The former Playmate-turned actress, 51, made the admission while reflecting on her Academy Awards debut in 1997, which came with an embarrassing lesson in how to dress in couture outfits after she was made the gaffe in a Valentino gown she was given to model. She told ‘Live with Kelly and Mark’ when Kelly Ripa, 53, asked her what her big “takeaway” was from attending the Academy Awards: “Well the funny thing is, I went to the Oscars once. “They invited me when I was the It girl. They invite the It girl each year…