'Big Bang Theory' Star Johnny Galecki Makes Public Debut With 21-Year-Old Girlfriend

Johnny Galecki made his first public appearance with 21-year-old girlfriend Alaina Meyer Monday.

The Big Bang Theory star and his new girlfriend were photographed in Los Angeles Monday, a couple of months before making their relationship public in July via Instagram.

According to E! News, the couple first made things official when Galecki posted a black-and-white image of himself laughing with the caption "Michigan bound" and crediting her for the image.

The couple also shared photos of each other Monday, just before the Emmys.

According to the outlet, the model visited her new boyfriend on the set of The Big Bang Theory recently, which is currently filming its last season.

Meyer also revealed on Instagram back on Sept. 1 that the couple shares matching tattoos. In a photo, Meyer's arm has a "JG" written in large block letters with a skull underneath.

Galecki also sports an "AMM" tattoo with a heart underneath it. The tattoo is written in bad black ink and looks like it is dripping down his hand. The caption for the image reads, "Gone country and branded by babe."

Since they started dating the couple has been hitting the road, enjoying several trips together that have taken them away from Los Angeles.

In August, Meyer shared a photo of the pair in front of the Waldorf Astoria Hotel in Chicago looking great together. One week later, she shared a photoof them at the Santa Barbara Bowl before attending a Jack White concert.

Though no signs indicate that Alaina might make an appearance in the final season of Big Bang, Galecki does have a history with his former co-stars. back in his days on the original run of Roseanne, Galecki and co-star Sara Gilbert dated for some time.

He also had a two-year relationship with Big Bang co-star Kaley Cuoco, though the pair broke up in 2010 and remain very close friends. Galecki was one of the Big Bang Theory cast members to attend Cuoco's wedding to Karl Cook over the summer, posting a congratulatory message for the couple at the time.

"Deepest congrats to the newlyweds," Galecki wrote, posting a photo from the wedding standing in between the new couple. "Love you both so much [Kaley Cuoco] & [Karl Cook] So moved by tonight."

The Big Bang Theory returns for its twelfth and final season Monday, September 24 at 8 p.m. ET before heading to its regular timeslot Thursday, September 27 at 8 p.m. ET on CBS.