Pregnant Kate appeared on the The Today Show in the States wearing an engagement ring, so it wasn't too long before the presenter spotted the sparkler and quizzed her on it.
"I'm engaged! It just happened a week ago. I'm so glad you noticed. I haven't really announced it. I feel like the announcement feels so silly. I was just waiting for someone to notice," Kate revealed on the show.
Showing off the ring with her perfectly polished red nails, Kate explained the proposal was: "'Very sweet. It was very romantic," but didn't give anything else away.
Expecting their first child together this summer, Kate and Matt have been together for a year.
By Tara Gardner