The singer — who has kept a low profile since Spears released her book — has built a “normal” life in Montana with Jessica Biel, a source says

PHOTO: LEON BENNETT/GETTY

Justin Timberlake is getting back to work.

On Wednesday, the pop star and actor stepped out for the Hollywood premiere of his new film Trolls Band Together. At the event, Timberlake walked the red carpet, where he posed with his wife Jessica Biel, as well as *NSYNC bandmates Lance Bass, JC Chasez, Joey Fatone and Chris Kirkpatrick, who recently reunited to record “Better Place” — their first new song in more than 20 years — for the film.

The outing came nearly a month after his ex, Britney Spears, released her bombshell memoir, The Woman in Me, in which she looks back on their relationship and breakup, writing that she had an abortion 20 years ago because Timberlake “didn’t want to be a father.”

Lance Bass, JC Chasez, Chris Kirkpatrick, Justin Timberlake and Joey Fatone at the Trolls premiere on Nov. 15.GILBERT FLORES/VARIETY VIA GETTY

Since that news broke, Timberlake, 42, has kept a low profile amid the Trolls promotional cycle. But a source says that’s due to the recently ended SAG-AFTRA strike: Timberlake’s promotion of Trolls, which included a recent screening and photocall with a smiling Biel, 41, by his side, was “upended more by the strike than by Britney concerns,” says a source.

On Friday, Timberlake posted a photo with Biel and his former bandmates from the event on Instagram — his first since the Spears book.

“So proud to celebrate the new @trolls movie and album with the crew. Gotta say this is my favorite so far 🙏🏻 Has been good to be back with my boys,” he captioned the carousel.

Biel also posted on Instagram Friday, writing: “The boys are back! So much fun celebrating #TrollsBandTogether. In theaters today!”