On the latest Carpool Karaoke, Late Late Show host James Corden took a ride to belt out a few of Christina Aguilera's best with the singer herself, with a surprise appearance by actress Melissa McCarthy.

Corden and Aguilera started off with some of the basics, jumping right into the single "Fighter," which allowed Corden to learn how to add the right amount of growl. He asked Aguilera about her time on The Mickey Mouse Club in the early '90s, where her cohorts included N'Sync's JC Chasez and Justin Timberlake, actor Ryan Gosling, and former teen pop rival Britney Spears. When asked whether she had a crush on Timberlake, Aguilera tried to keep it vague but hinted it might have been mutual.

"There was like...me and Britney...well, you know...there was like a 'thing' back then," she said. Stumbling over her words a bit, she offered an explanation of Timberlake's charms pretty simply. "He had swag."

Obviously, Timberlake and Spears wound up dating. "Right, that worked out wonderfully," Corden quipped.

As the duo started on Aguilera's '02 hit "Dirrty," Melissa McCarthy popped up in the back seat just in time to recite Redman's verse. "I've been back here the entire time!" she joked afterward. The singer then tried to teach Corden and McCarthy how to be true divas, showing off her four-octave vocal range in the process. 

Aguilera will appear in the McCarthy-starring  Life of the Party—co-written by McCarthy and husband Ben Falcone, who directed—on May 11.