Gwen Stefani and Blake Shelton's relationship doesn't seem to be cooling down.
On Saturday, the couple flew to Nashville, Tennessee, to celebrate a very special occasion -- the engagement of one of Shelton's former Voice teammates, RaeLynn.
PHOTOS: RaeLynn Is Engaged!
The country crooner helped plan the ugly sweater-themed party for RaeLynn and her fiancé, Josh Davis.
The bride-to-be, whose real name is Racheal Lynn Woodward, took to social media to share some silly snaps of her guests decked out in holiday gear in the party's photo booth.
"Thank you @AmandaCraigST and @blakeshelton for hosting the BEST engagement party/shower," the 21-year-old singer wrote, adding the hashtag "#destinedtobeadavis."
"Squad," another caption read.
WATCH: Blake Shelton & Gwen Stefani Are 'Perfect For Each Other,' According to Adam Levine's Wife
Hours before the celebration began, RaeLynn shared photos of her party prep.
"Yes, me and Joshua are having a Christmas themed engagement party," she captioned an adorable selfie. "Call me Cindy Lou Who."
RaeLynn announced her engagement to Davis in October, flashing her gorgeous sparkler in a photo she posted to Instagram.
"MEET MY HANDSOME FIANCE," she wrote. "Future Mr. and Mrs. Joshua Davis! Can't believe I get to marry my best friend."
WATCH: RaeLynn Reveals Blake Shelton and Miranda Lambert's Marriage Advice
Earlier this month, ET caught up with RaeLynn on the red carpet at the CMT Artists of the Year Awards, where she gushed about the marriage advice Shelton and his ex-wife, Miranda Lambert, gave her once they heard the exciting news.
RaeLynn has remained close with Shelton after competing with him during season 2 of the singing show, and she's been on the road touring with Lambert.
"I talk to both of them. You know, they're grown-ups. You handle things," she said of her relationship with the former couple. "[They said] 'It's all about when you find the right person, you gotta kinda go with it.' They've both been so supportive."
She also revealed she's a huge fan of Shelton's new relationship with Stefani, saying, "I think it's awesome! I mean, she's Gwen Stefani. They're both great people."
Shelton, 39, and Stefani, 46, were spotted out and about in the Los Angeles area earlier this week before taking off to the Music City. While the No Doubt frontwoman was shopping for Christmas presents in Van Nuys, her beau was seen hanging out with her dad, Dennis Stefani, at her parents' home in Westlake.
WATCH: Gwen Stefani Goes Christmas Shopping While Blake Shelton Hangs With Her Dad