Cee Lo Green and his longtime girlfriend Shani James are engaged, People

reports.

The former Voice coach proposed to James nearly a year ago at the studio where he was recording his upcoming album Heart Blanche. "I went and purchased a ring that we had seen together, maybe four or five months or so prior," Green told the magazine. "I went back and purchased the ring and I just kind of had it stashed away in some old equipment. And I said, 'Will you reach in there and grab something for me?'"

"It was the most beautiful diamond ring I had ever seen in my life. It was lit up by a light," added James. "I said, 'What is that?' He just looked at me and said, 'Well...?' And I was just like 'Oh my goodness.'"

"I said, 'Babe, I can't believe it.'" James continued. "He said, 'You've been such a good woman. You're such and amazing person. You're my life partner. You're my best friend. I want to share the rest of my life with you.'"

Green, 41, said he's grateful for how James has always stood by his side. Last year, he pleaded no contest to furnishing a controlled substance in a 2012 case in which a woman accused him of drugging her drink before sexually assaulting her.

"I appreciate her openness and willingness to love unconditionally," he said. "She's been so sweet to me through a number of different trials that come to test the resilience of a union to deem whether it's worthy or not, whether it's durable or strong enough."

This will be Green's second marriage. He was previously married for five years to Christina Johnson, with whom he has a son and two stepdaughters.