'This Is Us' News & Updates: Mandy Moore and Milo Ventimiglia Treat Fans With a Duet [WATCH]

Taking a quick break from acting, NBC's "This Is Us" stars Mandy Moore and Milo Ventimiglia treated their fans with a special impromptu performance. The two nailed the "The Prince of Bel-Air" theme song while they were in the show's kitchen set.

Glamour recently visited Moore and Ventimiglia on the set of their new TV series, "This is Us." In the show, Moore plays Rebecca while Ventimiglia plays as Jack. And then, quite surprisingly, the two broke out into a song during a light moment.

Rapping the "Prince of Bel-Air" theme song is a trip down memory lane for Ventimiglia. It can be recalled that back in 1995, he played as one of the party guests in the popular sitcom's episode entitled "Bourgie Sings the Blues." Moore chimed in when Ventimiglia started going with the lyrics, and when the actor said he was a fan of the show, Moore admitted that she was too.

"That was my first paying gig," Ventimiglia revealed to the crew. He also revealed how Will Smith considered him as a part of the family and he will always remember how the veteran star welcoming to everyone in the cast and crew. He also mentioned that Smith's son Jaden shares the same birth date as him.

The "This is Us" drama series was created by Dan Fogelman. The show is getting great feedbacks so far, and the stars are happy to entertain their new fans.

Last month, Screener reported that the NBC drama series scored the highest viewership ratings followed by the political drama series "Designated Survivor." The rating skyrocketed just after three days of DVR release and on-demand viewing.

"This Is Us" airs every Tuesday night on NBC at 8 p.m. ET. Watch Moore and Ventimiglia's impromptu performance below.