Olivia Rodrigo Celebrates 21st Birthday With Peekaboo Little Black ...

It feels like just yesterday Olivia Rodrigo got her driver’s license, and now the pop singer has reached legal drinking age.

Today, the Grammy winner celebrates her 21st birthday, which she rang in Monday night with a few of her famous friends, including Conan Gray, Finneas O’Connell, and Tate McRae.

Rodrigo documented the festivities on Instagram, with pics from the celebration that highlighted her peekaboo party dress. For the event, the “Vampire” singer sported a plunging halter-style LBD held together with skinny bedazzled belts wrapped around her waist. The bikini-like top was formed with two loops of gathered material, woven through a leather strap that sat on the songwriter’s neck. The skirt of the dress featured long slits down the sides, making the sheer look even cheekier.

The High School Musical: The Musical: The Series alum paired the birthday dress with matching stilettos that had a dramatic flared heel. And to coordinate with the sparkling straps across her torso, Rodrigo accessorized with diamond-encrusted silver hoops and sterling rings, which were seen up-close in the first snap of her slideshow.

In her caption, the hitmaker comically wrote, “Today is my last day of being able to underage drink (hypothetically) !!!!” (If you’re unaware: The lyrics to Rodrigo’s song “Making the Bed”—about getting drunk at a club—went viral last fall, when fans realized she wasn’t old enough to drink at the time.)

Other snaps from the slideshow saw Rodrigo hugging her friends and cutting slices of a lavender cake. Here’s to another stylish trip around the sun, Olivia.