The Big Bang Theory star Johnny Galecki and partner Alaina Meyer have announced that they are expecting their first child and "are absolutely over the moon". 

Galecki shared the couple's happy news on Instagram, writing: "We are absolutely over the moon to announce that we will soon be welcoming a little one into this crazy and wonderful world."

"We ask that you please respect our privacy during this celebratory time for us and our families," the actor continued. 

"There truly is love out there for all. We hope ours is the ember of yours, as we feel yours is the ember of ours."

The Big Bang Theory series finale airs in the US on Thursday, May 16. The comedy phenomenon will come to a close after 12 years and 279 episodes.

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