Ben Affleck looked happy as he posed with girlfriend Ana de Armas for a selfie on Sunday, August 16, a day after celebrating his 48th birthday together.In the black-and-white photo, the Oscar winner grinned as he stood behind the Knives Out actress, 32. She captioned the snap with two pink hearts.The pic came after the couple were spotted taking a spin on a new BMW motorcycle that de Armas reportedly gifted Affleck for his birthday.