Two YouTube stars are mourning the loss of their father. The Dolan Twins announced on social media that their dad Sean lost his battle with cancer. Grayson and Ethan Dolan posted photos of him to Instagram saying how much they love him and will miss his presence. The twins first announced his diagnosis on their YouTube channel in 2016. InsideEdition.com's Mara Montalbano (https://twitter.com/MaraMontalbano) has more.