The 34-year-old actor decided to use his ALS ice bucket challenge to reveal he and Dawn, 35, are expecting their first child together.
In the video posted on his Twitter page, the star douses himself in ice-cold water before going on to nominate - with a cheeky glint in his eye - 'baby O'Porter'.
He then turns the camera on his wife, who pours a mini cup of iced water over her baby bump!
The couple married in a low-key ceremony in 2012. Dawn's maiden name is Porter but after the wedding she started using the name of O'Porter.
This has got to be up there with the best pregnancy announcements of all time, right?
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