Tom Briglia, WireImage
"I have a very special guest tonight," the sequin bra and booty short-wearing performer announced to the audience. "... Lady Gaga is here!" she revealed to a chorus of sustained screams of excitement.
Britney pointed out her fellow pop superstar, who was sitting in the elevated VIP section (as pictured to the left), for all their mutual fans to see.
Gaga waved and bowed down to her pop predecessor, who was in turn blowing Mother Monster kisses, before reportedly dancing to Spears' set and downing drinks from behind the velvet ropes.
After her presence was revealed, Britney fans proceeded to chant Gaga's name during a performance break. But Brit Brit showed she was a good sport about sharing the spotlight when she took to Twitter after the show to give Gaga another shout out.
"So amazing to have the beautiful @LadyGaga at the show in AC tonight. Love you girl," she posted to her page.
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