Big Bang Theory star Johnny Galecki to become a father for the first time

He asked fans to 'respect our privacy'.

Big Bang Theory star Johnny Galecki is expecting his first child with partner Alaina Meyer.

The actor, 44, announced the news in a post on Instagram alongside a selfie of him and Meyer, 21.

Galecki wrote: “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. 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.”

Galecki stars as socially awkward physicist Leonard Hofstadter in science sitcom The Big Bang Theory, which is coming to an end later this month after 12 years and 279 episodes.

Earlier this week, Galecki – alongside his co-stars Jim Parsons, Kaley Cuoco, Simon Helberg, Kunal Nayyar, Mayim Bialik and Melissa Rauch – was immortalised in cement outside Hollywood’s TCL Chinese Theatre.

The actors were the latest stars to place their hand prints outside the Los Angeles landmark.

Galecki and Meyer went public with their relationship in September 2018 and made their red carpet debut together at the E! People’s Choice Awards in November.