Gwen Stefani and Blake Shelton attend the 2016 Vanity Fair Oscar party in Beverly Hills on February 28, 2016. Blake Shelton has proposed to Gwen Stefani , but his fellow recording superstar turned down his offer. The couple have been together for six months. The Voice coaches both divorced their respective spouses last year. RadarOnline.com reported Shelton stashed a $1.2 million engagement ring in a box of Kentucky Friend Chicken during a recent outdoor picnic, but the surprise didn't get the reaction he hoped for from Stefani. "Gwen was very touched, but said she had to wait to make sure it was right for the kids," an insider told the media outlet about the singer who has three young sons -- Kingston, 10, Zuma, 7, and Apollo, 2 -- with her ex-husband Gavin Rossdale . Stefani and Shelton made headlines earlier this week when they performed together at the Billboard Music Awards.