"Congrats to you and Blake on your marriage!," one fan wrote in response. "Your happiness brings joy to so many!'
"Did you get married I'm very confused?" another fan added.
On Saturday night, Stefani joined Shelton at the 2016 Country Jam festival in Grand Junction, Colorado. The two Voice coaches performed their duet "Go Ahead and Break My Heart" during Shelton's set. Stefani even got some stage time of her own, getting the crowd jumping while performing No Doubt's "Hella Good."
"I don't know how I'm going to follow that," Shelton said after her performance – kissing his rocker girlfriend on stage.
They celebrated Shelton's birthday all weekend, with a party beginning on Shelton's private jet and spilling over to his trailer. Stefani's brother Todd and sister-in-law Jill joined in on the fun – documented on Stefani's Snapchat account. Shelton dawned "Happy Birthday" glasses and a "40" crown. Among his many gifts? A guitar-shaped cake and personalized wine glasses of him and Stefani.
Stefani even went as far to change her Twitter avatar to a picture of her beau,"my favorite person I ever met" on Twitter.
Both musicians ended long-term relationships last year, with Shelton and Miranda Lambert divorcing in July and Stefani and husband Gavin Rossdale announcing their split several weeks later.
Stefani's sons – Kingston, 10, Zuma, 7½, and Apollo, 2 – spent the weekend with Rossdale in Hawaii, for Father's Day.