Johnny Galecki Teases ‘Emotional’ Performance With Bill Gates on ‘Big Bang Theory’ (Photo)

“Doesn’t happen every Thursday. Not on camera anyhow,” actor says of upcoming episode

It sounds like this week’s episode of “The Big Bang Theory” is going to get a little heavy.

Thursday’s episode of the CBS sitcom features a guest appearance from Microsoft bigwig and philanthropist Bill Gates, and “TBBT” star Johnny Galecki divulged a bit about the appearance via Instagram ahead of its airing.

“I get emotional with Bill Gates tonight,” Galecki wrote, in a caption for a photo of Gates surrounded by the “Big Bang Theory” cast.

“Doesn’t happen every Thursday. Not on camera anyhow,” Galecki added.

According to CBS, the episode — dubbed “The Gates Excitation” — features Penny (Kaley Cuoco) receiving the opportunity to host Gates at work when his company wants to partner with her pharmaceutical company.

Meanwhile, Leonard (Galecki), Also, Leonard, Koothrappali (Kunal Nayyar) and Wolowitz (Simon Helberg) “do everything in their power to meet him,” while Sheldon (Jim Parsons) “thinks he is the victim of an April Fool’s prank,” according to CBS’s synopsis of the episode.