The I Want It That Way hitmaker proposed to his girlfriend, fitness expert and aspiring actress Lauren Kitt, on a small island in the Florida Keys - and she accepted.
Carter tells People.com, "I had the ring in my pocket for two weeks. I was like, 'I don't want it anymore!' It was driving me insane. I just wanted to get it out of my hands and on to hers...
"She said, 'Yes,' and I'm, like, 'I don't know what to do.' She said, 'You're supposed to put it on my finger.' So I did. I was in shock."
The couple has been dating for four years.