Jason Castro is going to be a dad. The former American Idol finalist has announced he and wife Mandy Mayhall are expecting a baby girl this summer. "Now, I am excited to announce that there will be a new addition to the Castro family! My wife and I are expecting our first child this August," Castro wrote on his blog. "We just found out yesterday that it is going to be a girl! haha That makes me laugh... What am I going to do with a sweet little girl?! Probably just smile a lot... I cannot wait!!!" Castro -- who finished fourth on American Idol's seventh season in 2008 -- married Mayhall in a January 2010 ceremony in his hometown of Rockwall, TX. The couple got engaged in 2009 after Castro popped the question on Halloween while and Mayhall were dressed as characters from Beauty and the Beast.