Kaia Gerber's boyfriend Austin Butler served as the ultimate Instagram boyfriend as he shot sizzling snaps of his bikini-clad girlfriend in the pool on New Year's Day.The 21-year-old posed up a storm in her sexy swimsuit as her boyfriend took photos of her during her getaway to Cabo San Lucas with her family.During breaks from their photo shoot, Kaia and Austin, 31, were the epitome of couple goals as they packed on the PDA in the pool. Instagram boyfriend! Kaia Gerber's boyfriend Austin Butler served as the ultimate Instagram boyfriend as he shot sizzling snaps of his bikini-clad girlfriend in the pool on New Year's DayKaia clung to her beau as he leaned down to press his lips against hers beneath the sunshine.The statuesque stunner looked sensational in a bronze bikini top paired with taupe bottoms as she soaked up the sun with shades concealing her eyes.