"Yes its true!" Jason said in a Twitter message. "WAHOOOOOOO!!! Molly is going to be a MOM and TY a BIG BROTHER! YIPPEEEEEEE!"
He did not say when the baby is due or whether it is a boy or girl.
Jason, who has a 7-year-old son Ty from a previous relationship, originally proposed to Melissa Rycroft on Season 13 of "The Bachelor," then broke up with her on the air and pledged his love for Molly.
Jason and Molly married in February 2010.