Johnny Galecki had a brilliant response to Kaley Cuoco implying their relationship was boring

• Kaley Cuoco hinted that her relationship with Johnny Galecki was boring.
• The hint came in a Valentine's Day Instagram post dedicated to her husband, Karl Cook.
• Cuoco and Galecki dated for two years while starring in "The Big Bang Theory."

Johnny Galecki made his ex-girlfriend Kaley Cuoco laugh out loud when he responded to her hint that their relationship was boring.

Cuoco posted a touching Valentine's Day tribute to her husband, Karl Cook. "Happy 5 years to the weirdest person I know!" she wrote. "I don't remember a moment before you entered my life.. what a boring life that must have been! I love you."

Since Cuoco and Galecki dated for roughly two years, Galecki took this personally. The actor commented, "Um."

Cuoco replied to her ex-partner and now good friend, "LOL."

Cuoco and Galecki starred in the long-running CBS comedy "The Big Bang Theory" as Penny and Leonard. Their characters were love interests throughout the show, culminating in their marriage in season 10.

Cuoco and Galecki themselves dated from 2007 to 2009. However, they tried to keep their relationship as private as possible.

Cuoco told CBS Watch in 2010: "It was a wonderful relationship but we never spoke a word about it and never went anywhere together. We were so protective of ourselves and the show and didn't want anything to ruin that."

Though they split up, Cuoco and Galecki have remained close friends, and they continued to work together amicably on the set of "The Big Bang Theory" for 10 years.

Cuoco has said she was convinced that after they broke up, the show's creator, Chuck Lorre, wrote in more sex scenes between Penny and Leonard purely to mess with her and Galecki.

In a 2015 appearance on "Watch What Happens Live with Andy Cohen," Cuoco said: "Johnny is actually one of my best friends. It's a situation that ended well. I understand sometimes it doesn't. It could have gone horrible. He's one of my dearest friends."

Cuoco also said in that appearance that her husband at the time, Ryan Sweeting, loved Galecki. She and Sweeting, a former tennis player, were married in 2013 and divorced in 2016.

In late 2016, Cuoco began dating Cook, the son of the billionaire Scott Cook. They were engaged in 2017 and married in 2018.

In 2019, Cuoco described their marriage as "unconventional" because they didn't live together. In fact, they moved in together only last April to quarantine together.

Cuoco was recently nominated for a Golden Globe for her new TV series, "The Flight Attendant." Fans adored her reaction: She burst into tears at the news.