With just a handful of episodes left, The Big Bang Theory might be setting up a finale similar to How I Met Your Mother's controversial ending. There are just ten episodes to go before the show officially wraps up its final season. However, given where The Big Bang Theory's narrative is currently with Leonard (Johnny Galecki) and Penny (Kaley Cuoco), it seems like the series could end the same way it began.

The Big Bang Theory is revisiting the possibility of Leonard donating his sperm after he was approached by Zack (Brian Thomas Smith) and Marissa (Lindsey Kraft) regarding the matter in "The Propagation Proposition." Long-time viewers of the show will remember that the very sequence from the sitcom's pilot episode saw Leonard and Sheldon (Jim Parsons) at a sperm bank hoping to donate in exchange of money. The trip didn't pan out after the latter chickened out, but Leonard remained open to the idea. More than a decade later, he's offered the opportunity to finally push through with it if he commits to helping Penny's ex-boyfriend and his new wife have a kid by donating his sperm since Zack is infertile.

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Obviously, the Zack and Marissa subplot has something to do with The Big Bang Theory's ongoing conflict between Penny and Leonard about whether or not they want to have kids. Earlier this season, Penny declared that she doesn't want to have kids, ever - something that's new to her character since she had been open to the notion in past seasons. This broke her husband's heart who has been dreaming of having a family with her since the day they met. Leonard haphazardly agreed to his wife's terms, but is still clearly hung up on the idea of the having kids. It's unclear where The Big Bang Theory writers are going with this storyline but the last we saw, it seems like Leonard was genuinely interested in pushing through with the treatment as it will allow him to pass his genes albeit in an unconventional way. Penny has also given her blessing after she was initially repulsive of the idea, meaning that her husband is clear to do whatever he wants.

Assuming that Leonard successfully donates his sperm giving Zack and Marissa a baby while he and Penny remain child-less, then in many ways The Big Bang Theory will be following How I Met Your Mother’s divisive ending.

The Big Bang Theory Penny Leonard and Baby Problem

The fellow CBS sitcom's finale infamously ended on Ted (Josh Radnor) and Robin (Colbie Smulders) back together in 2030, all for the sake of paying off setup in the show's first episode. While the New York-based series kicked off the series with a tease that the two might end up with each other, its narrative meandered throughout the years, leading the characters to different paths and partners; Robin married (and, in another controversial turn, divorced) Barney (Neil Patrick Harris), while Ted ended up with the mother, Tracy (Cristie McConnell), who it was hurridly revealed died of an unknown illness. At the very end, though, Ted still got together with Robin in a final scene homaging How I Met Your Mother's pilot. However nostalgic as the ending was, it disregarded everything that happened throughout the course of the series (a result of the ending being partially filmed after season 2), ruining it for a lot of people.

As it stands, The Big Bang Theory likewise seems to be building to a finale inspired by the show's beginning, not the twelve years since. Executing a similar ending like How I Met Your Mother will undoubtedly spawn varying opinions from viewers of The Big Bang Theory; most of the loyal supporters of Penny and Leonard already think that this whole child-or-no-child subplot is an unnecessary way to complicate the Hofstadters' relationship considering how out of the blue it feels. Pulling a full circle finale would be cool but not when it’s in the disservice to the characters.

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The Big Bang Theory air Thursday nights on CBS.