Adam took a photo of Victoria's Secret model Behati sunbathing in a red bikini and Lakers cap.
Captioning the photo, Adam said: "My two favourite laker fans" with a baby, milk bottle and basketball emojis.
The photo is confirmation that the couple are expecting their first child.
Reports of baby joy for the couple first emerged last month but they did not confirm the rumours at the time.
It looks like a family was always on the cards for Adam and Behati, who married in Mexico in July 2014.
Behati recently revealed during an appearance on The Lowdown with Diana Madison: "Since I was a little girl I've always wanted a big family, I'm an only child so I wanted like ten kids, for sure!"
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