The Olympic champion's girlfriend Susie Verrill has given birth to their first child - a baby boy who they've called Milo.
Susie announced the news at 9.40 this morning (Monday October 20) by tweeting an adorable photo of their new baby's hand gripping her finger, along with the caption:
"And then there were three..."
And then there were three... pic.twitter.com/FtYMVdHj8Q
- Susie Verrill (@rugbycupcakes) October 20, 2014
Susie's brother Paddy then revealed that they have named their son Milo.
- Paddy Verrill (@paddyverrill) October 20, 2014
Greg and Susie's friends started to suspect that Susie might be in labour last night when the usually prolific tweeter failed to live tweet the X Factor.
"Hang on, @rugbycupcakes isn't live tweeting X Factor. Has she finally gone into labour?!" wrote one.
Another replied: "I mean.. this has to be the only reason.. GO ON SUSIE"
Greg previously revealed to Parentdish that Susie's due date was October 16 - a few weeks after his sporting season ended, meaning he and Susie had a bit of time to prepare of the arrival.
"I just can't wait to be around baby," he told us in August. "I think the first time baby recognises me and smiles is going to be one of the most amazing times of my life to be honest.
"I also can't wait to play with baby. I was quite lucky, although my dad worked a lot, whenever he was free he would play sports with me and my brother and I can't wait to do that with my child."
Congratulations Greg and Susie!
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