While "Big Bang Theory" Season 8 actress Kaley Cuoco-Sweeting is being plagued by divorce rumors, her on-screen boyfriend Johnny Galecki is actually the one who has been suffering from relationship issues.

The 39-year-old television and film actor reportedly ended his romance from "Pan-Am" star Kelli Garner this week after more than two years of exclusively seeing each other, Us Weekly has learned.

An insider close to the couple told Us that Galecki and Garner may have called it quits, but the celebrity couple are still the best of friends.

"Johnny and Kelli are still best friends" the source said, noting that the breakup was totally amicable.

The "Big Bang Theory" actor and the "Man of the House" actress first stepped out in public in March 2012 to confirm the dating rumors that surfaced that time despite their best efforts to conceal their romance from the public.

Galecki's breakup from Garner comes just months after they were seen enjoying their Mexico vacation in January. Insiders said that the two really enjoyed their getaway and that they weren't shy to show their affection for each other publicly at the time.

Prior to which, the couple was spotted attending Galecki's on-screen girlfriend Kaley Cuoco's wedding to Ryan Sweeting.

It can be noted that Galecki and Cuoco also dated on the past, but they still remain to be the best of friends after their split.

"We're dear friends, still. Kaley's not just an ex, she's a part of my life," Galecki said in a November 2013 interview. "I just don't like to speak about it. And not because I'm trying to be enigmatic; I just worry that it will conflict with people's acceptance of (our characters) Leonard and Penny. I get the curiosity, but I don't want to distract from the story."

On Monday, Galecki attended the Emmys, where his co-actor Jim Parsons bagged the award for lead actor in a comedy, reported The Celebrity Cafe.

Meanwhile, it was revealed recently that Galecki, Cuoco and Parsons have renegotiated their contracts for the "Big Bang Theory" Season 8 since their show consistently received stellar ratings last season. They are now to be paid $1 million for each episode, according to PopCrush.

"The Big Bang Theory" Season 8 is set to premiere on Sept. 22, 2014.