In the episode entitled "The 43 Peculiarity" Sheldon drove Howard and Raj crazy with secretive behavior and Leonard had to deal with Penny's new life at college.
Even with one course, Penny has assignments and Leonard came face-to-face with his biggest fear --- a fellow student who happened to be male.
The expected jealousy began in earnest when text messages from the guy interrupted an evening together. Learning they are working on a presentation together, the nerdy physicist started to complain about the constant communication.
Where have we seen this before? Oh yeah, during Friends, that's right. The co-worker of Rachel's that broke up her relationship with Ross, due to sheer jealousy.
Instead of going down the Rachel and Ross route of taking a break, Penny stuck it out and ultimately put Leonard out of his current misery.
After following the student down the stairs of the apartment building, he posed as just another neighbor. Leonard poured it on about how big and tough Penny's boyfriend is.
When Penny found him doing so she stalked off and straight into silent mode.
When they next met in the hall, they engaged in a discussion about the situation. That is when the bombshell got dropped:
"It's hard sometimes," Leonard says to begin to explain his stupidity. "Everywhere you go, guys hit on you, even if I'm standing right there. And they are all taller than me. Why is everyone taller than me," he whines.
Penny answered with some frustration in her voice. "Leonard, why do you always do this to me? Listen, you're the one I'm with. You know I love you. Will you please relax because you're driving me crazy."
Boom goes the dynamite, as the saying goes. How to handle this?
Leonard's face registered shock and awe, as his lips trembled and he said, "This is the first time you said you love me." Penny's answer was, a hesitant and shocked, "Yeah".
Agreeing to treat it as no big deal, the two immediately go their separate ways. Leonard's voice cracked as he told himself, "She loves me".
Lurking however, is a flirtatious advance made by Alex, Sheldon's hot assistant. The problem for Leonard will come from the disconnect between what he thinks are innocent remarks and Alex's true attempt at flirting.
You just know that Penny will learn about it. She already has a bug up her butt about Alex and made that plain. Read: Penny gets jealous, Leonard benefits
We all know this will become the next big plot line, the only question is whether it will end the season with a wedding or a breakup?
What do you think? When this season began, Penny was on the verge of breaking up with Leonard who was pressing her for a commitment. That melted away and culminated in this. Can this couple survive their histories, differences and Sheldon's inevitable intrusion?
CBS airs new episodes of The Big Bang Theory each Thursday night at 8:30 p.m. ET/PT. Image: CBS/The Big Bang Theory