AceShowbiz -

After dating on and off since the third season of "The Big Bang Theory", Leonard and Penny may take their relationship to the next level in this currently airing sixth season. According to Johnny Galecki who plays the experimental physicist, the couple will have a special moment in the upcoming Valentine's Day episode.

"Next week we start shooting the Valentine's Day episode," the Emmy-nominated actor tells The Hollywood Reporter. He goes on hinting at a possible engagement of the couple as saying, "It's a big one for Leonard and Penny - there might be somebody getting down on one knee."

Asked if the proposal will be successful, he coyly says, "I don't know if it'll work out, I'm just saying." As for the couple's relationship, he explains, "The ball is still in her court. The last couple of seasons have really been about her emotional inabilities. It's made that character of Penny a well-rounded one, and you'd assume it would always be Leonard's fault, but he's been a pretty good partner to her."

When describing the Valentine's Day outing, Galecki says it will be very much in the vein of their latest Christmas episode. "We never started doing holiday event shows until two or three seasons in, when we did the Christmas episode. That was a big hit, and we struck a chord of sentimentality with our audience, and we'll continue to do so," he elaborates. "The Valentine's Day episode will be that."

"The Big Bang Theory" airs every Thursday at 8 P.M. on CBS. The show has outperformed its own ratings with the last two episodes, scoring 19.3 million viewers on January 3 before topping it with 20 million viewers on January 10.