The 51-year-old couldn't wait to show off her massive rock while taking a selfie on Monday.
Wearing an unbuttoned neon cardigan, J Lo's cleavage wasn't what caught attention. It was her oversized rock that made everyone stop and stare.
Holding up her phone to snap a mirrored selfie, the mom of two casually flashed a multi-carat diamond ring.
The circular-shaped bling is clear in color with a silver band, completely different from the spare pink Harry Winston diamond that Affleck bought her for $2.5 million nearly 20 years ago.
"My favorite color is neon anything," she teased the photo while mentioning an upcoming project with Sephora but failing to acknowledge the ring on her finger.
As Radar reported, Affleck was photographed looking at engagement rings at Tiffany & Co on Monday.
He even brought his mom, Chris, and his 9-year-old son, Samuel — who he shares with ex-wife Jen Garner — along to help him shop for the diamond.
Attempting to go incognito, the Academy Award winner wore a mask and shades but he didn't fool photographers. They were anxiously waiting outside the pricey shop to see if he walked out with a ring.
While it didn't appear that Affleck pulled the trigger, the fact he was looking is huge because this wouldn't be the first ring he's bought for J Lo.
Die-hard Bennifer fans will recall, he popped the question during their first round of dating in 2002. They were scheduled to walk down the aisle in 2003 but canceled their wedding last minute, citing too much media attention.
Affleck and J Lo officially pulled the plug on their engagement in January 2004.
Fast-forward to 17 years later. They found their way back to each other after J Lo ended her relationship with ex-fiancé Alex Rodriguez.
While he remains salty over their April breakup, Affleck and J Lo have been attached at the hip ever since.