The 32-year-old singer had popped the question to the dental nurse during a romantic getaway in Paris on December 23, reported contactmusic.
"This is the best Christmas present I've ever had. I'm going to be a dad with the love of my life... I am seriously the happiest I've ever been right now.
"Me and the (Blue) boys had our album out, we've done The Big Reunion (TV show), and we're touring. Now having a baby on the way is like everything's falling into place," he added.