06/15/2012 at 11:45 AM EDT
is going to be a grandfather – again!
During Friday's episode of The Talk
, Osmond's eldest son, Don Jr., broke the news that he and his wife Jessica are expecting their first child.
"I wanted to take a minute to say I'm very grateful and I feel blessed that I had the opportunity to break you into fatherhood," said Don Jr. to his father, who was a surprise celebrity guest on the episode. "I wasn't the first to make you a grandfather, but Jessica and I have your fifth grandbaby.”
After hugging his son and tearing up, Osmond, 54, stood up and said, "Now I feel really old!"
Osmond's Father's Day surprise episode of The Talk
airs Friday at 2 p.m. ET/1 p.m. PT/CT.