“Happy birthday to my favorite person I ever met @blakeshelton,” Stefani posted on Twitter.
On Instagram, Stefani shared a photo of Shelton as a kid with the caption, “Happy birthday to @blakeshelton literally my favorite person.”
Stefani shared several photos from the birthday party on Snapchat. E! Online posted a few of the images, which include Shelton’s birthday sunglasses and a pair of wine glasses.
The wine glasses feature caricatures of Stefani and Shelton, complete with the attire they wore to the 2016 Oscars.
Shelton also received two birthday cakes. One was a standard chocolate cake from his band, while Stefani gave him one shaped like a guitar.
Stefani wasn’t alone in expressing her excitement for Shelton’s 40th birthday.
In response to Stefani’s sweet messages, Shelton thanked his girlfriend for celebrating his birthday in style.
“Now THIS is how you start your 40’s!!!!!!!” Shelton posted on Twitter. “Thank you @gwenstefani for everything…”
Later that evening, Stefani surprised fans with a special duet during Shelton’s concert in Grand Junction, Colorado. According to Billboard, Stefani joined Shelton onstage for a rendition of their single, “Go Ahead and Break My Heart.”
The song is from Shelton’s latest album, If I’m Honest.
‘I guess if I had one birthday wish for me personally… I wish I could rock,” Shelton told the crowd. “I wish I was one of those type of artists that could rock but I can’t… For my birthday I wish I could hear an artist who could rock, that’s my birthday wish.”
Stefani then took the stage and sang a No Doubt track, “Hella Good,” for concert goers.
Shelton posted a message on Twitter following the concert and thanked fans for a great birthday.
“I possibly witnessed the coolest and craziest thing of my life tonight… Thank you Colorado and @gwenstefani!!! Look up the videos!!” he wrote.
Based on their affectionate interactions on social media, it is clear that Blake Shelton’s relationship with Stefani is as strong as ever. Does this mean that a wedding — and a baby — is in their near future?
The Voice stars began their relationship back in November. Ever since they got together, a source revealed that they are “really happy together.”
Although a wedding might be in the cards, the two are “not putting pressure on themselves.” Instead, the insider stated that they are “just enjoying life.”
“Everyone is thrilled because they’re both incredibly nice people,” the source continued.
At this point, it is unclear whether or not Shelton and Stefani will get married soon. As far as a baby is concerned, fans will have to wait and see what happens in the coming months.
In light of all the wedding and baby rumors, Stefani tried to clear the air during a radio interview on The Tommy Show.
When asked about tabloid rumors surrounding her romance, Stefani denied reports about a coming wedding and shared that she is approaching her relationship with Shelton “one day at a time.”
Shelton went through a divorce last summer with his longtime partner Miranda Lambert. A month after Shelton’s divorce, Stefani split with her husband, Gavin Rossdale.
Fortunately, both singers found comfort in each other and used their budding romance to deal with their emotional breakups.
Considering their sweet duet and birthday wishes, it doesn’t look like their romance is going to slow down anytime soon.
Tell us! Where do you think Blake Shelton and Gwen Stefani will be in six months — engaged, married, or expecting a baby? Let us know in the comments below.
[Photo by Kevin Winter/Getty Images]