He "seemed different, like he was 'free' almost," an onlooker tells PEOPLE of seeing Chris Pratt at the after-party for the Ingrid Goes West premiere at Avenue L.A. in late July

By Melody Chiu and Lindsay Kimble
August 07, 2017 04:32 PM

Just two weeks before publicly announcing his separation from wife Anna Faris, Chris Pratt seemed relaxed and happy at the premiere and after-party for his former Parks and Recreation co-star Aubrey Plaza‘s new movie, Ingrid Goes West.

A partygoer tells PEOPLE that Pratt “was friendly, outgoing and playful” at the after-party, adding, “I was surprised by how he looked to actually be having fun, and that he was there voluntarily.”

Another onlooker who attended the bash at Avenue L.A. adds that “Chris seemed different, like he was ‘free’ almost.”

Premiere Of Neon's "Ingrid Goes West" - Red Carpet
Credit: Alberto E. Rodriguez/Getty Images

“He said no to pictures though, which is weird because he always likes to take photos with fans,” the onlooker says. “But he was in great spirits and was mingling with everyone he knew, like Amy [Poehler], Aubrey [Plaza] and that whole crew. They were together the whole night.”

The party marked a Parks and Recreation reunion, with Pratt, Poehler and Plaza also hanging out with castmate Retta.

Los Angeles Premiere-INGRID GOES WEST
Credit: Michael Kovac/Getty
Premiere Of Neon's "Ingrid Goes West" - Red Carpet
Pom Klementieff and Chris Pratt
| Credit: Alberto E. Rodriguez/Getty Images

In their social media statement on Sunday night, Pratt, 38, and Faris, 40, said, “Anna and I are sad to announce we are legally separating. We tried hard for a long time, and we’re really disappointed.”

“Our son has two parents who love him very much and for his sake we want to keep this situation as private as possible moving forward,” the statement continued. “We still have love for each other, will always cherish our time together and continue to have the deepest respect for one another.”

Premiere Of Neon's "Ingrid Goes West" - Red Carpet
Aubrey Plaza and Chris Pratt

The former couple was married for eight years, and share a son, Jack, who will turn 5 in August.

The pair had been plagued with rumors of tension over the past year, and Pratt was recently spotted without his wedding ring in public.

A source tells PEOPLE Faris sometimes seemed unhappy while Pratt was away filming and that the separation was often hard for her to bear.