Looks like Gwen Stefani is getting an early start on her Las Vegas residency!
On Sunday night, Shelton tweeted that he was going to perform a free show at the House of Blues in Vegas after the ACMs and was bringing along some “friends.”
And he certainly delivered with fellow Voice coach Kelly Clarkson and girlfriend Stefani joining him.
His lady love took the stage around 1:30 a.m. Monday and performing several songs, including “Hollaback Girl” and “Hella Good.”
“The crowd was going crazy for Gwen,” a concertgoer tells PEOPLE.
Be sure to check out PEOPLE’s full ACM Awards coverage to get the latest news on country’s big night.
Stefani wore jeans, boots and a green jacket while letting her blonde hair loose for the night as she led the crowd into a soaring rendition of “Hollaback Girl.”
But boyfriend Shelton had a special request, walking onto the stage – much to the excitement of the crowd – and asked her to sing “Hella Good.”
After a bit of a convincing, the songstress relented — if he agreed to sing it with her.
“I’m only doing it if you do it with me,” she said.
Toward the crowd, Stefani said, “So, I know it’s weird that I’m up here… but we all have one thing in common and it’s that we love Blake Shelton very much.”
During the song, Shelton, red Solo cup in hand, helped Stefani sing the chorus. He also jokingly danced for his girlfriend.
Later, on Monday night, Stefani shared a series of Instagram posts in which she gushed about her “date night” with Shelton at the ACMs.
“Proud,” she wrote on one with a sweet heart emoji, while an additional post shouted out designers Rob Zangardi and Mariel Haenn — the pair responsible for her chic red jumpsuit look.
RELATED VIDEO: Cute Couple Alert! Blake Shelton Brings Gwen Stefani As His Date to the ACMs
The couple recently opened up in separate interviews about their relationship, revealing both had considered marrying the other.
Shelton, 41, admitted to CMT’s Cody Alan that he has marriage on his mind..
“I think about it. I don’t think it’s anytime soon or anything,” Shelton said when asked about tying the knot. “The more time that goes by, I guess, the closer you’d be getting to that.”
Stefani, 48, revealed she also had wedding bells on her mind during an appearance on The Ellen DeGeneres Show last week.
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DeGeneres asked if rumors that the two were planning on getting married soon were true, a question which the singer skirted around by asking DeGeneres for advice.
“I love being married,” the host said. “I think you should get married.”
DeGeneres dropped the topic but told her to keep it in mind.
“I do,” she replied. “I think about it all the time.”