“They’re coming up on their four-year anniversary, but Blake and Gwen still act like lovebirds,” a source tells PEOPLE of the pair, who began dating in fall 2015 while both starring on the NBC series.
“They’re really happier than ever, and being back where they first fell in love has been fun for them,” the source says. “They can’t believe how quickly time has flown by, and their relationship is very solid. Blake worships her, and Gwen feels very secure with him.”
“It’s like she never left,” the source says of Stefani’s Voice homecoming, adding, “Her kids also love going to set.”
Stefani first appeared on the singing competition in late 2014 for season 7 with fellow newcomer Pharrell Williams. The former No Doubt singer, who replaced Christina Aguilera, would go on to coach seasons 9 and 12.
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Recently, Shelton told PEOPLE about how quickly he and Stefani’s time together has passed since they were first romantically linked.
“It’s actually shocking that it has already been that long,” he said in June. “It’s kind of a blur. It still feels like it’s pretty new to me. I guess it is, relatively. Four years isn’t forever, but man, it seems like it just happened in no time.”
And when it comes to The Voice, the country singer knows his girlfriend is a tough competitor. “This will be her fourth time on the show, so she’s no stranger to it. She knows what she’s doing,” he said.
“I’m glad that she’s already feeling competitive. Of course, I’m not going to let her win. I’m going to have to win, but I’m going to have to do it in a way that she doesn’t feel like I beat her,” Shelton continued. “I don’t know if that’s possible or not because I definitely don’t want to upset her — that’s not going to pay off for me in the long run.”
Season 17 of The Voice will premiere on NBC on Sept. 23.