Kyle Sandilands and fiancee Tegan Kynaston expecting baby

Kyle Sandilands and his fiancee are expecting their first child, but the radio host has revealed serious details about the pregnancy.

Kyle Sandilands will become a dad for the first time at 51.

The popular FM radio shock jock announced the news on his KIIS breakfast host with fiance Tegan Kynaston by his side.

“We are having a baby, can you believe it,” Sandilands said. “We are having a friggin baby. I couldn’t be happier.”

It comes just weeks after the pair became engaged while holidaying in Port Douglas.

Showing his softer side, Sandilands thanked his partner, whom he first met when she worked for his company.

“Congratulations sweet heart,” he said. “Thank you babe.”

Sandilands celebrated his milestone 50th birthday last year while Kynaston is 35. He will be 51 when the baby is born.

Parents to be.

“He has been excellent,” Kynaston said of Sandilands. “And he is very emotional about it, very happy, already looking at cribs online … he wants a little bed crown for above the crib.”

The announced came just before 8am with a lengthy chunk of 16 minutes dedicated to the exciting news.

Kynaston said she has just reached the three month pregnancy mark with the baby due in August, which would make it a Leo star sign.

They are yet to find out the gender of the baby.

“We don’t know the sex yet so we are not going to worry about that yet,” Sandilands told listeners. “We know maybe what we will call him or her. I either want a girl or a little gay son. Tegan feels it doesn’t have to be homosexual.”

Sandilands joked about Kynaston’s breasts growing in size due to the pregnancy.

KIIS breakfast co-host Jackie ‘O’ Henderson is already a mother and joked: “Can I call you daddy from now on?”

Kyle Sandilands and Tegan Kynaston.

The pair became engaged a few weeks ago.

Later though, Sandilands got serious.

“This may be a bit personal but at one stage we thought maybe it had been lost and then we went to the ultrasound in Cairns and the woman there put all of the jelly on her and we didn’t tell her we were worried,” Sandilands explained. “And then she goes, ‘now there is the heartbeat’ and I just yelled out ‘it is alive’. When you first start having one, you don’t know all of the changes and all of the weird feelings.”

Sandilands recently spoke to Confidential about his thoughts about one day becoming a father.

He said it was crunch time as the couple made a decision about parenthood.

“It’s definitely not off the cards,” he said. “It has never really been on my priority list and I think that is just because I was that kid that dragged around my childhood issues from my parents’ divorce and this and that.”

Sandilands has long spoken about his difficult childhood and the fact he spent time sleeping in his care homeless in his teenage years. He has also previously stated he believes he is too selfish to have children.

“When you think about it, because my mates have all got kids … young ones, and now I feel a bit left out,” he said. “At first when they were showing me videos of this kid walking, I was like, ‘who cares? Big deal’. But now I look forward to it when my god child comes over. My girlfriend has got friends as well with young kids and they are not as horrible as I first thought, they are actually quite fun.”