After what felt like an eternity, Spring has finally arrived and Sienna Miller [1] is celebrating with a fun day at the beach, naturally. The 37-year-old actress is currently on holiday in Tulum, Mexico, and on Wednesday, she showed off her toned figure in a black bikini. Sienna looked relaxed as she caught some rays and walked along the beach, though it's unclear if her new boyfriend, Lucas Zwirner, joined her.

Rumours that Sienna was dating [2] the 28-year-old David Zwirner Books editor first began swirling in December 2018, when the two attended her ex Tom Sturridge's birthday party in London. It wasn't until the following month that the couple basically confirmed the reports when they were spotted kissing in NYC. According to W Magazine, Sienna's new beau [3] is a Yale graduate and oversees 25 book releases a year as editorial director of his father's publishing house. Could Sienna's glow have something to do with her new romance?