Affleck, 47, and de Armas, 31 — who met while shooting their upcoming thriller Deep Water — spent Saturday night together and the Knives Out actress joined the actor at his home.
Earlier in the day, Affleck spent time with his three children, whom he shares with ex-wife Jennifer Garner: Violet, 14, Seraphina, 11 and Sam, 8.
Affleck and de Armas were also with each other on Friday in L.A., where he appeared to be helping her house hunt.
Pascal Le Segretain/Getty Images; Amy Sussman/Getty Images Ben Affleck and Ana de Armas
Last week, the new couple, who recently wrapped production on the upcoming film, arrived in the States after traveling together around Latin America.
“Ana was his tour guide and took him to all her favorite places. Ben seemed to love the trip. He was in a great mood and very friendly,” a source recently told PEOPLE. “They are definitely dating.”
While making Deep Water, which was filmed last year in New Orleans, Affleck and de Armas had an instant connection.
“They had great chemistry right from the start,” a set source told PEOPLE of the two actors, who play a married couple.
“Ben always seemed very relaxed and happy around Ana, but at the time there were no signs of romance,” said the set source. “He was very focused on making a fantastic movie. He arrived early and was one of the last people to leave.”