According to a Stefani source, Shelton, 40, and Stefani, 46, have yet to share the wedding date with their families, however, a Shelton source toldUs Weekly, "They want to get married before the end of the year."
During a recent On Air with Ryan Seacrest appearance, Stefani became flustered and basically stuttered when radio host Ryan Seacrest asked if she'd ever get married again.
"That is so funny. I don't know, God, I don't know. Any of those..." Stefani began with a laugh. "Everything is going so quickly. I just -- I'm in the moment and, um, I'm just -- look at me, you've got me tongue-tied. Stop it!"
Stefani's response suggests she's hiding some information about her love life!
"They are both very, very happy," a Shelton insider told Us. "Blake is having the time of his life with Gwen and feels so comfortable around her."
Stefani filed for divorce from her ex Gavin Rossdale -- with whom she shares sons Kingston, 10, Zuma, 8, and Apollo, 2 -- after 13 years of marriage in August 2015. Meanwhile, Shelton's four-year marriage to Miranda Lambert had ended one month prior.
Stefani and Shelton leaned on one another for support at the time, and what started out as a friendship quickly turned into a romantic relationship. The couple has been in love and inseparable ever since late October 2015.
"I look at this year and I think, I just feel so awake," Stefani told Seacrest in her radio interview. "I feel so alive and so grateful... this year has been so full of so much joy."
Another source previously told the magazine that Stefani and Shelton are looking to have "more low-key" weddings than their first go-arounds, maybe at Shelton's Oklahoma ranch or in his backyard.
"Gwen doesn't really care," the source had told Us, "she is just in love with Blake and their life together."
Shelton will be returning to The Voice as a coach alongside Adam Levine, Miley Cyrus and Alicia Keys when Season 11 premieres Monday, September 19 at 8PM ET/PT on NBC. Last season, Stefani served as the mentor for "Team Blake" during the show's famous "Battle Round."