Lifestyle Style Here's Why Sienna Miller Is Wearing a Gorgeous Engagement Ring The actress is sparking engagement rumors by wearing some big bling on her ring finger By Brittany Talarico Brittany Talarico Brittany Talarico is PEOPLE's Deputy Style Director, where she oversees the brand's digital Style and Beauty coverage. This includes running lead on the Met Gala, which is among PEOPLE.com's top-trafficked red carpet events every year, interviewing the industry's top influencers (including all the Kardashian-Jenners), and breaking A-list celeb news (a New Jersey shore native, it is no surprise that her favorite interview ever was with Bruce Springsteen). Brittany is a style contributor to People Every Day Podcast and has represented the brand on national TV programs including Good Morning America and The CW's two TV specials on the British Royals. She joined PEOPLE from Cosmopolitan in 2013, where she was an Associate Editor. People Editorial Guidelines Published on September 14, 2017 12:49 PM Share Tweet Pin Email INSTARimages.com; Inset: Splash News Sienna Miller made a bling boo-boo. The actress was snapped leaving the set of her play Cat on a Hot Tin Roof in London Wednesday, wearing a very large, very sparkly engagement ring, which sparked rumors that she and director boyfriend Bennett Miller were taking their relationship to the next level. But the actress, who plays the role of Maggie in Benedict Andrews’ adaptation of the famous Tennessee Williams’ play, simply forgot to take off the oversize ring prop she wears as part of her character’s costume. (See it in the photo below.) Johan Persson “She messed up big time,” a source tells PEOPLE. “It’s very funny. She was rushing off to dinner and forget to take her prop ring off! She’s obviously feeling silly about it now. She didn’t realize until she was in the cab.” RELATED PHOTOS: Steal Sienna Miller’s Boho Style with These 11 Looks And while the ring may be just a prop, it definitely looks really good on Miller’s finger. The actress, 35, and the Foxcatcher director, 50, have been dating for the past year and are careful about keeping their relationship very private. Earlier this year, Miller opened up to The Guardian about how she approaches fame way different in her 30s and chooses to ignore any rumors that surround her, which has made her a “more powerful” woman. “I feel like if anyone wrote anything now, it would not bother me,” she shared. What do you think of the actress’ diamond prop mix-up? Share below!