OK! Exclusive: Chace & Carrie Celebrate Something Big!

What better way for Chace Crawford and Carrie Underwood to spend some quality time then at the fourth anniversary party for celeb-friendly NYC hot spot Marquee. After all, this is the club where the two lovebirds began their whirlwind romance back in October.

Despite the large crowd trying to get a look at the Gossip Girl star and his country singing cutie at their table on the dance floor, these two only had eyes for each other. American Idol champ Carrie, 24, and Chace sneaked in a bunch of kisses and cozied up next to each other all night. One witness tells OK!, “They certainly didn’t care who was gossiping about it!”

The two stayed at Marquee until about 2 a.m., though they only made their way to the dance floor once. And since Carrie is only in town until Saturday, friends of Chace reveal to OK! that the pair plan on spending some quiet time together. “They'll probably just have a night with just the two of them,” the friend says about the couple's plans for the rest of the weekend.

Back in October, Chace told OK! that he met Carrie through "friends of friends." He also blushingly admitted, "she's very classy."

And while this classy couple was holding down the front of the club, another adorable couple was in the back Red Room having their own fun. After her National Treasure: Book of Secrets premiere, Diane Kruger and boyfriend, Joshua Jackson, danced the night away and were joined by Josh’s two brothers.