The Absolute Worst Thing Penny Ever Did To Leonard On The Big Bang Theory

The Big Bang Theory may have had fans laughing for an incredible 12 seasons, but the characters weren't always the best people.

The four nerdy male leads — Leonard (Johnny Galecki), Sheldon (Jim Parsons), Howard (Simon Helberg), and Raj (Kunal Nayyar) — were naturally somewhat socially inept, with their behavior often crossing a line into completely unacceptable territory. But it wasn't only the awkward scientists who crossed a line: Penny (Kaley Cuoco), their bubbly blonde neighbor, also had some decidedly uncool moments throughout the series. While she and Leonard ended up together, their relationship was fraught with twists along the way, and it took a few seasons for them to couple up and actually make it stick.

Penny wasn't always the loving friend and partner to Leonard that she grew to be by the series' end. In the early days, she dragged man after man through her life, using Leonard as a shoulder to cry on when things inevitably turned sour — despite knowing full well that he was always in love with her. Even though they were an unlikely match, she had feelings for him early on as well, but opted not to tell him the truth, which could have saved them both years of relationship futility.

Their first attempt at being a couple ended horribly, when Penny dumped Leonard very publicly at a bowling alley in the season three episode "The Wheaton Recurrence." Leonard had told her he loved her, and because she wasn't ready to say it back, Wil Wheaton (as himself) swooped in and manipulated her to break up with Leonard rather than stringing him along. It was a brutal episode, with Leonard left heartbroken at the end of it, feeling as though he'd permanently lost the woman he wanted more than anything to be with.

When they did reconcile, Penny seemed to take advantage of Leonard at every turn, expecting him to be the one to compromise all the time so that she could get her way, at one point saying it was his job to make her happy and her job to let him. It's a pretty selfish and immature attitude toward a relationship, which most healthy adults know is something that only works if both parties compromise and take care of one another equally.

Although Penny did grow up a lot by the end of The Big Bang Theory, even in the final season her selfish streak often shone through. The couple tied the knot at the beginning of season nine (and again a few episodes later for the benefit of their friends and family), finally moved in together, and seemed to be moving forward with their lives. Then, early in season 12 Penny dropped a bombshell on Leonard: she probably wasn't ever going to give him kids. Leonard seemed devastated by the revelation, obviously having hoped to become a father one day.

Now, of course, there's absolutely nothing wrong with a woman not wanting to become a mother. Not everyone is cut out for it, and plenty would prefer to live a child-free life. It's certainly not uncommon these days for young women to decide not to have children. What is not okay, however, is waiting until you've already been married for a few years before telling your husband. If Penny had been less selfish, she would have told Leonard she didn't want children before they tied the knot. Granted, knowing Leonard, he would have married her anyway, because he just loved her that much. But at least he would have done so knowing he might never have kids, and she wouldn't have taken the choice away from him.

After Penny's big reveal, another storyline in season 12 saw Penny's ex-boyfriend Zack (Brian Thomas Smith) come back into the picture, wanting Leonard to donate sperm for his wife as they were having trouble conceiving. While we recognize just how bizarre that request was, Leonard was initially excited by the prospect, and agreed with Penny's blessing. Penny, though, later made it abundantly clear — although apparently not to Leonard, who needed Amy and Sheldon to spell it out for him — that she actually wasn't cool with the situation, denying Leonard another opportunity to become a father, even if only biologically.

Sure, this may have been for the best, as Leonard would never have been the child's dad, and he might have ended up longing for a child who could never be his own. But it was still a bit strange how Penny readily agreed to let Leonard donate sperm, and then tried to sabotage the procedure in any way she could.

Fortunately for Leonard, there's a twist at the end of the tale when we learned in The Big Bang Theory's finale that Penny, after a night of drinking with Sheldon, had come home to her husband and forgotten all the rules from high school sex-ed, leading her to accidentally become pregnant. While she didn't seem totally psyched by the fact that she was going to become a mother after all, she did seem to be fairly content with the way things had turned out, and Leonard was over the moon that he'd get to be a dad.

Fans never got to see Penny adjust to motherhood or the couple's little bundle of joy, but they seemed truly happy by the end of the episode (despite Penny eating and then vomiting copious amounts of fish), with Penny beaming from ear to ear as Sheldon told the tale of how Leonard had been planning how great their kids would be from the moment he met her. All's well that ends well, we suppose — but it sure seems like Penny could have made Leonard's life a lot easier if she had been less inclined to focus almost exclusively on her own needs.