Rumors have been swirling this week that the 46-year-old actor-writer is dating Petra Collins after his Instagram followers took notice of a photo he posted of himself with the 25-year-old artist back in February. Theroux shared the pic on the same day he was photographed at the Adam Selman show during New York Fashion Week.
"Justin is still heartbroken," a source tells ET, adding that Theroux is not one to play the field but rather prefers to be in a relationship and is still reeling over the fact that his marriage to Aniston did not work out.
Meanwhile, another source tells ET that the former Leftovers star has been relying on his friends to help him cope with the breakup, and notes that Theroux "had a nice time" during his "guys' trip" to Paris, France, earlier this month.
When abroad, the newly single star attended the Louis Vuitton runway show during Paris Fashion Week, and while his pals might have been eager to hit the town and flirt with women, Theroux was friendly rather than flirty, according to the source.
A third source tells ET that Theroux is, however, ready for "his next phase in life."
As for his relationship with Collins, the third source says the two met through Selena Gomez when "they all hung out together."
"She is artsy and edgy and loves the New York nightlife," the source says of Collins before calling out that Gomez -- who's also friendly with Aniston -- recently unfollowed the artist on Instagram.
Despite his apparent heartbreak, the source says Theroux is confident that his breakup with the 49-year-old actress was the right decision as their relationship had been "going south for a long time."
“He felt confined by their relationship. He wasn't interested with Jen's everyday scheduled life of yoga classes, eating healthy,” the source continues. “Justin is a free spirit and loves his time alone. Justin had a need for independence.”