This will be Jason's second child; The new baby will join his son Ty, 7, from a previous marriage.
"He's been so excited to be a big brother," Jason, 36, says, revealing that he told Ty he was getting a sibling through a family game of hang man.
"The answer was 'Tyler is going to be a big brother,'" Jason recalls. "He's been asking me for years. He's always wanted to be a big brother. So we played the game and he looked at Molly and I and said 'Really?' Molly made him a t-shirt that says 'Big Brother' on it and he's really proud. He wore it to school."
Jason and Molly met during season 13 of The Bachelor, and caused controversy when Jason initially proposed to Melissa Rycroft, but later changed his mind during the season finale and asked for a second chance with Molly. The couple married in February 2010 and reside in Seattle.