'Big Bang Theory' star Johnny Galecki, 43, is dating a 21-year-old model

Big Bang Theory star Johnny Galecki has confirmed he is dating 21-year-old model Alaina Meyer.

On Tuesday, the 43-year-old actor shared a photo of himself and his new leading lady on Instagram.

"Last night was wonderful," he captioned the sweet photo.

The pair have been linked together since at least July, and two weeks ago Meyer revealed they have matching tattoos. He appears to have her initials, as well as a love heart, on his hand, while she has his, alongside a skull, on her arm.

"Gone country and branded by babe," Meyer shared on Instagram, captioning photos of their ink.

Galecki was dating his Big Bang Theory co-star Kaley Cuoco for two years before they split in 2010.

The two fell in love after meeting on set, however the relationship ended due to the pressure of keeping their romance a secret.

The two remain on good terms, and Galecki even attended Cuoco's recent wedding to Karl Cook.

Following the nuptials, Galecki shared a sweet Instagram photo of himself and the bride.

"Couldn’t be happier for my fake wife @normancook and @mrtankcook whose words brought us all to tears last night," he captioned the photo. "So much love for you both."

Galecki also dated his Roseanne co-star Sara Gilbert in the 1990s. He and Gilbert played on-screen couple Darlene Conner and David Healy.

Catch up on all of The Big Bang Theory Season 11 on 9Now.