The pair, who spent Valentine’s Day weekend at Las Ventanas Al Paraiso resort in Cabo San Lucas, spent more time soaking up each other than soaking up the sun.
“They were inseparable,” an eyewitness tells PEOPLE. “They held hands everywhere they went.”
Penn, 53, and Theron, 38, who stayed in a private ocean view villa, complete with its own pool, also enjoyed cozy al fresco meals in the resort’s restaurant.
“Before dinner one night, they held hands and took a stroll around the pool, looking at the beach,” says the eyewitness. “They looked completely enamored with each other.”