Lady Gaga always seems to be busy, but she was able to take time out her heavy work schedule to take in a Britney Spears concert over the weekend. Mother Monster sat in the audience at Brit's Femme Fatale show in Atlantic City, N.J. on Saturday night.

As always, Gaga was pretty noticeable, wearing a leather biker cap, a black bra and houndstooth tights. She sat in a private section on the floor, and Spears was so honored by her presence that she announced that Gaga was at the concert after her 'I'm a Slave 4 U' performance.

With a huge smile on her face, Spears said, "I have a very special guest tonight ... Lady Gaga is here!" The crowd proceeded to scream at the top of their lungs as Gaga and Spears waved at each other. The divas then raised their hands up in the shape of hearts at one another. How sweet!

Gaga took in the show with two male friends. After sipping down a few drinks, which were probably whiskeys since this is Gaga's spirit of choice, Gaga got down with her buddies as Britney sang her latest single 'I Wanna Go.'

Although the fans in Atlantic City obviously came to see Ms. Brit, they couldn't help themselves during a set break and they began to chant Lady Gaga's name, according to E! Online. A huge crowd then swarmed the singer in hopes of capturing a photo of the famous concert-goer. Gaga later exited during Brit's encore in order to avoid another fan fiasco, but she was seen partying it up and gambling at the Borgata Resort later that night.

After the show, Spears tweeted at Gaga, writing, "So amazing to have the beautiful @LadyGaga at the show in AC tonight. Love you girl. -Britney." Brit's boyfriend Jason Trawick was also at the show, but unlike a recent show in New York, he wasn't treated to a lap dance this time around.

Watch Britney Spears Introduce Lady Gaga at Her Atlantic City Show

Watch Lady Gaga Dancing to Britney Spears' 'I Wanna Go'