The A-list couple was spotted taking some tropical getaways after starring together in the upcoming film Deep Water.
They made their relationship Instagram official Thursday with some gorgeous Polaroids as they enjoyed a romantic desert retreat to celebrate her 32nd birthday.
De Armas, 32, and Affleck, 47, packed on the PDA, wrapping their arms around each other in a desert selfie.
Another snap shows her snuggled up to the shirtless Good Will Hunting star, as they gazed at the sunset.
She captioned the photos: ‘Thank you all so much for the birthday wishes and love! Cheers to another great year.’
The Knives Out star was beaming as she blew out the candles on her chocolate cake while sporting a birthday headband.
The couple enjoyed the cake with some wine on their patio before heading out for a desert hike.
They decorated their abode with some colorful balloons, including a gold mylar ’32’ and a mermaid.
Affleck and de Armas were spotted last month vacationing together in her hometown of Havana, Cuba.
They were seen sharing some sweet moments on the beaches of Costa Rica shortly after.
The lovebirds met in the fall while filming Deep Water in New Orleans, in which Affleck plays a man suspected of murdering his wife’s (de Arma) lovers.
They’ve since been isolating together at the Gone Girl actor’s house in Los Angeles since returning from Costa Rica.
A source told People: ‘They seem to have a great time together. They order delivery food and groceries and only leave the house for walks around the neighborhood with their dogs.
‘Ben looks incredible happy. They are flirty and goofy. Ana always has a huge smile around him.’