Us Weekly revealed that Lena Dunham and Jack Antonoff are proof that exes can still be friends. The Girls alum joked about the musician in an Instagram Story on Sunday, June 17. Dunham even wished him a happy Father?s Day. The pair appeared to be having an exchange over social media or FaceTimed over the weekend.Just last week, the pair got flirty on Instagram. Dunham made a post about her cat in the late hours and Antonoff responded, ?Why are you awake.? Dunham added: ?Cuz it?s the prime time to catch you on the gram, four eyes.? Us Weekly confirmed in January that Dunham and Antonoff, 34, had split after five years of dating. Dunham opened up about their breakup in an essay published by Vogue. The pair inspired Taylor Swift?s song ?You Are in Love,? which was released off her 1989 album.