Blake Lively Wore an LBD with a Subtly Sexy Keyhole Cutout

Last night, Blake Lively took to the streets of New York City to support her BFF Taylor Swift at Saturday Night Live's afterparty wearing a chic alternative to the plunging-neckline dress. At first glance, Lively's LBD might have appeared conventional, but the keyhole-style frock was sexy in a subtle way with a strategic flash of skin.

The ribbed sweater dress featured a high neck with a cutout below stretching across the top of her chest. Lively layered on a gold necklace and added a pop of color to her monochromatic look with a pair of emerald drop earrings and a sapphire heart-shaped ring. Further dressing up her otherwise minimalistic outfit, Blake accessorized with a sparkly shoulder bag and platform heels with deep purple accents on each toe, which coordinated with her husband Ryan Reynolds's suit jacket.

A black face mask and glossy waves provided the finishing touches to her look.

During last night's episode of SNL, Swift performed the 10-minute version of "All Too Well" from her rerecorded album Red (Taylor's Version). And the next morning, she teased the release of a new music video from the same album, crediting Lively as the director. "SURPRISE! NEW MUSIC VIDEO TOMORROW at 10am ET," Swift captioned a short clip, featuring a three-tiered cake with two claw marks running across the white icing. Seconds later, a hand wearing a ruby and diamond ring (similar to Lively's) grabs a chunk from the center. "I finally got to work with the brilliant, brave, & wickedly funny @blakelively on her directorial debut. Join us as we raise a toast, and a little hell."