In town to promote Living Proof hair care products, Aniston and Theroux shared a busy weekend together – hopping from a Broadway show to Sunday brunch.
On Sunday, Aniston, 44, and Theroux, 41, were photographed holding hands as they walked to brunch at Fred's At Barneys New York, a restaurant that serves American and Italian cuisine inside the high-end department store.
Wearing a green jacket and sunglasses, Theroux seemed to be enjoying the sunny May day as Aniston covered up with an oversize hat and sunglasses.
After brunch, the couple browsed bathing suits in the swimwear section.
Aniston's busy weekend began on Friday, when she saw Bette Midler on Broadway in I'll Eat You Last with friends, including Kathy Najimy.
A source tells PEOPLE that Aniston "had a great time" at the show and "laughed a lot."
"She wasn't able to come backstage but told [a theater staffer] to tell Bette how much she enjoyed the show," the source added.
After the play, it was off to Trattoria Dell'Arte, where Aniston dined with a group of girlfriends. The actress sipped nothing but Pellegrino throughout the evening.
Saturday was another night out for Aniston, who visited Japanese hotspot Nobu with Theroux.
According to a different source, Aniston, Theroux and the rest of their group indulged in martinis and yellowtail sashimi with jalapeno, black cod with miso and rock shrimp tempura.
"[Aniston] was really sweet and happy," the source adds about the actress who sat in the back area of the restaurant. "When people saw her, they went crazy."
Reporting by MARY GREEN, EMILY STROHM & MABEL MARTINEZ