The pop superstar, who turned 28 on Friday and performed at the famed Roseland Ballroom in New York City, celebrated the end of her very special day with her beau and hinted that his presence was unexpected.
"Another amazing birthday moment. I love surprises!" the G.U.Y. crooner captioned a sweet black and white snapshot of the lovebirds.
The Chicago Fire actor is leaning in to give his ladylove a sweet kiss, while the songstress is smiling as she gazes at the camera.
While the singing sensation didn't share a photograph of any presents from Kinney, Gaga posted a glimpse of a very special gift from Donatella Versace.
After a bunch of outfit changes throughout the day, Mother Monster donned a space-inspired white long-sleeve leotard, a long platinum blond wig and mile-high pale pink tentacled platforms to the post-show festivities.
Earlier in the evening, Gaga kicked off a seven-night engagement at the famed New York City venue and pal James Franco was in the audience.
"HAPPY BDAY, GaGA!!!!" the actor enthusiastically captioned a photo of the duo backstage on his Instagram account.
The special weekend continued for the A-list couple and they showed their support for Franco at his Broadway show Of Mice and Men on Saturday evening.
"I love my puppy purse, had a lovely time at Of Mice and Men tonight," Gaga tweeted along with a snapshot posing in her flower patterned pink frock, matching hat and cute doggie handbag. "I love going to the theatre."