NEW YORK: Lena Dunham is on a mission. The Girls star was shocked to discover that her boyfriend Jack Antonoff used to date sultry Scarlett Johansson and now she’s grilling the tight-lipped rocker about what else he hasn’t told her. Lena has dated the guitarist with the pop band fun for nearly two years. But she had no idea he and Scarlett were high school sweethearts until she stumbled across a picture of them on the website Old Loves. “She’s beautiful, he’s beautiful, but it was just so surreal to be looking through this blog and then there’s my boyfriend.”–Show