Less than a week after appearing live on "American Idol," No Doubt paid a visit on Monday night to the kids on "Gossip Girl."

But Gwen Stefani and her band didn't play for any of the students at Constance Billard or St. Jude's. Instead, the California rockers took part in a flashback episode featuring a young version of Lily van der Woodsen, the mother of rich girl Serena (Blake Lively).

That plot twist meant Leighton Meester didn't get to catch No Doubt in character as queen bee Blair Waldorf, nor while she was just hanging out on set. In fact, for a while, Meester wasn't even aware the band was making a "GG" cameo appearance.

"You wanna know something?" Meester told MTV News while on the set of the music video for her collaboration with Cobra Starship. "I didn't even get to see No Doubt, and I didn't even know that they were gonna be on. Somebody told me that they were coming on my show. And they performed in L.A. while I was working in New York. That's what happened!"

On Monday night's episode, No Doubt appeared as an '80s band called Snowed Out, who performed for young Lily and friends at a club in Los Angeles. The episode has been positioned as a possible pilot episode for a "GG" spinoff. No Doubt's cameo has been part of a re-emergence for the band after several years on the sideline. They're set to begin a North American tour later this month.

So while Meester was disappointed that she didn't get to check out No Doubt on set, she'll certainly have the opportunity to take in Stefani's band at some point in the future.

"I love her," Meester said. "And I love No Doubt. That was one of the first albums I had, and I still know every word. I think she's awesome, and the music they make is great. I really love that style, too, because it's a woman singing, and it's not totally pop. It's really fun and very strong and cool."