Pepper Potts is back in action — and some bling on Gwyneth Paltrow’s finger sparked buzz.
Avengers: Infinity War executive producer Jon Favreau posted a picture on his Instagram posing next to Paltrow and Robert Downey Jr., who plays Pepper’s longtime on-and-off love Tony Stark (a.k.a. Iron Man), on set in Georgia.
Other pictures of the actress on set show her wearing a large ring on her finger as she rehearsed lines with Downey and Hulk actor Mark Ruffalo. The actress kept it casual in white high-waisted pants and a black tank with her hair loose and no makeup.
Paltrow, 44, has been dating writer-producer Brad Falchuck, 46, since 2014, but sources have previously told PEOPLE said the two aren’t engaged.
But — spoiler alert! — there may be wedding bells in the future for Stark and Potts, since sources say Paltrow was spotted wearing a different, sizeable diamond engagement ring while filming in character. Stark had a ring in hand and was planning to propose to Paltrow’s character in a scene in Spider-Man: Homecoming.
The third Avengers installment, Infinity War, due out in 2018, has already wrapped filming, so it’s unclear whether Paltrow’s scenes are a late add to that movie or part of a fourth film. Favreau served as director for the standalone Iron Man movies and also plays the superhero’s bodyguard.
Although all three of them appeared briefly in the latest Spider-Man, this would be a homecoming of sorts for Paltrow, who hasn’t had a significant role in the Marvel movies since 2013’s Iron Man 3.
Paltrow’s appearance on set comes after the Goop CEO said she was taking a step back from acting to focus on running her popular lifestyles brand website.
“It’s just one of those things,” she said of focusing on her company. “I was so lucky: I had an incredible acting career, but I had this deep passion to produce content and make great products and curate things. It sort of evolved slowly and had a long gestational period and now it’s like, a real business.”
This article originally appeared on PEOPLE