Watch Christina Milian And Josh Peck Party Like It's 1999 On 'Lip Sync Battle'

It was J.Lo vs. Sisqo.

For a lot of us, our first memories of Christina Milian and Josh Peck are from the late '90s, when Christina was a Disney "Movie Surfer" known as Tina, and Josh was a supporting actor on Amanda Bynes' Nickelodeon sketch show, The Amanda Show. So, it's appropriate that, not only were the Grandfathered co-stars matched up for last night's new episode of Lip Sync Battle on Spike, but they also both performed hits from 1999.

Christina started things off with the Jennifer Lopez jam "Waiting for Tonight," complete with sexy group choreography and leather pants. We think J.Lo would be proud.

Christina was good, but Josh really stole the show with his performance of Sisqo's "Thong Song." He donned silver hair and a recreation of Sisqo's all-white ensemble from the video to get down with some shorts-clad dancers. At one point he even pulled out a couple of thong straps of his own.

We're feeling pretty '90s nostalgic right now. How about you? Planning a Y2K music video marathon this weekend? Maybe take your Beanie Babies out of storage? Don't forget to crimp your hair!

Watch both performances below: