After months of speculation about its whereabouts, Jessica Biel showed off her (alleged) engagement ring for paparazzi photogs who snapped the recently betrothed couple on a lunch date in Brentwood, Calif., Thursday afternoon.

Biel -- who was plenty camera-ready in a stunning aqua Twelfth St by Cynthia Vincent dress and styled ponytail -- flashed an enormous, vintage-looking square cut diamond on her ring finger, according to photos published in People magazine.

Biel reportedly showed off the the rock in mid-February at a Saturday Night Live afterparty following Timberlake's appearance. But the (recently) 30-year-old actress appeared solo -- and ringless -- at the Golden Globes in January, weeks after reports surfaced of a New Year's Eve proposal.

So where has the ring been hiding?

According to a late January tabloid report, Biel rejected Timberlake's first engagement ring and demanded an upgrade.

When Justin proposed to Jessica, she was disappointed with his choice of ring, a source reportedly told the Enquirer (via Celebitchy). Jessica isn't a fancy girl, but she wanted something stunning -- a bigger diamond that would impress her friends. Instead, Justin went more minimal, thinking she'd prefer something less flashy.

The report claimed that Timberlake was sympathetic to Biel's expectations.

He was very understanding, and told her that she deserves to have what she wants, the Enquirer source continued. To placate her, Justin has not only enlisted his mom for help with her ring, but he's going to propose all over again.

Biel and Timberlake's on-again, off-again relationship has prompted some to wonder if their eventual marriage will be for good. Garry Marshall, who directed Biel in Valentine's Day and New Year's Eve, spoke to Us Weekly about the engagement. And while his words were positive and supportive, there was a hint of skepticism.

We talk about [the engagement] a lot. I hope it all works out -- they are terrific kids, Marshall told Us Weekly of the couple. I love them both. I'm happy for her.

An unidentified source told Us Weekly that Biel and Timberlake were planning to marry this summer at a private estate.