“Oh, that’s a really good question," Stefani said. "The good news is that we still like each other a lot. That’s good. I don’t know. We’ll see what happens.”
The couple took home a joint CMT Music Award earlier this month and Shelton opened up to ET about their journey together.
"We've been together now for five years, believe it or not. We've worked together and we've written together," Shelton explained. "So at this point in our relationship, we're always looking for what's the next thing that we haven't accomplished yet."
"She's never not been supportive or a cheerleader, just the most encouraging person I've ever had in my life, on any level," he shared. "It's unbelievable how supportive she is. I tell her this all the time, and she doesn't realize it, but Gwen's one of these people that I learn so much from, because no matter what the situation is, she has a way of looking at something from every angle possible, and understanding if there's turmoil or something going on, instead of just jumping to conclusions or reacting, it's, 'Well, here's why they may feel that way.'"
"I've learned a lot from her -- to not be so reactive as I used to be," he continued. "She's definitely helped to calm me down, for sure."
When asked about marriage plans, Shelton told ET that their relationship was definitely headed that way.
"You know, I gotta say that we couldn't be happier, and we've never been doing better," he said. "Obviously, that's gotta lead somewhere, but I promise you, we won't break the news in any of the grocery store trash magazines."
"Gwen and Blake do so many fun activities with the boys and Blake plays with them like a big kid," a source told ET in August. "He seriously enjoys doing things with the kids like going to the movies, fishing, camping, and teaching them to horseback ride and boating."
"They are both working so much and are loving their life as a family," the source continued. "Blake has made Gwen's boys a huge priority in his life and cares for them like they're his own."
The singer admitted she was "obsessed" with her longtime love.
"I just never thought in my wildest dreams, on paper, a cowboy and a ska-like girl from Anaheim would be hanging out, but it works perfectly and we're just having so much fun and we just feel so blessed to be at this point in our lives," she said.
"I feel as if I spent the last four years healing, you know, trying to build my life again," she told Shape magazine. "Having a best friend like Blake to help me do that has been one of the greatest gifts."
Stefani also gushed over her simple pleasures with Shelton, which include playing tennis "badly" together and visiting his Oklahoma ranch.
"Spending time in the middle of America [on Blake's ranch] -- that's something I didn't expect," she shared. "The way we live at the ranch is really simple. There are watermelons that Blake planted and all my wildflowers. It's a nice contrast to L.A., although I do keep 20 chickens in the backyard here at home too."
For more on Stefani and Shelton's relationship, watch the video below: