Gwen Stefani & Blake Shelton Smooched On Stage For His 40th Birthday

Gwen Stefani and Blake Shelton can are no strangers to serving up peak #CoupleGoals. The pair has been open about their whirlwind romance since it first began on The Voice. At Shelton's concert in Colorado on his 40th birthday this weekend, Stefani celebrated by joining him on stage and giving the country crooner a big ol' kiss.

Stefani's short set was a surprise, according to Us Weekly. After Stefani, 46, performed "Hella Good," she leaned over and planted a kiss on Shelton. The birthday boy was clearly surprised by the whole thing: "What just happened?!" he said. "I don’t know how I’m going to follow that."

Later on that night, Shelton tweeted his appreciation, saying the performance made his birthday especially great.

The kiss wasn't the only surprise Stefani had planned to celebrate Shelton's milestone. The "Make Me Like You" singer also posted a throwback of Shelton as a youngster, and decorated their private jet with b-day swag, according to Us Weekly.

Gwen's own birthday is coming up in October. No pressure, Blake.