Young Sheldon Just Solved a Decades-Old Big Bang Theory Mystery

A traumatic moment from Sheldon Cooper’s upbringing was just reframed on Young Sheldon.

The incident in question was first alluded to in The Big Bang Theory Season 10, Episode 5, “The Hot Tub Contamination,” when Sheldon revealed to Penny why he always knocks three times before he enters a room:

More from TVLine

I was 13 years old, and on spring break from college. My mother was in bible study, I walked in the house expecting to find it empty, and I heard a sound coming from my parents’ bedroom. When I opened the door, I saw my father having relations with another woman…. We locked eyes, I ran to my room, and we never, ever spoke of it.

But that isn’t how it went down on Young Sheldon. In Season 7, Episode 4, “Ants on a Log and a Cheating Winker,” 13-year-old Sheldon and his mother Mary returned from their summer in Heidelberg — a stint in Germany that Big Bang previously told us happened when Sheldon was 15, but that’s neither here nor there….

In the tag scene, Sheldon returned home from his college dormitory, knocked on his parents’ bedroom door only once, then opened the door to find his parents mid-coitus.

Mary had just surprised George Sr. with a sexy Oktoberfest getup — which included a blonde, pigtailed wig — and when Sheldon came a-knockin’, Mr. and Mrs. Cooper were engaged in role-play.

Georgie and Mandy 'Young Sheldon' Spinoff Cast, Release Date, Everything We Know
Georgie and Mandy 'Young Sheldon' Spinoff Cast, Release Date, Everything We Know

Young Sheldon’s Georgie and Mandy Spinoff: Everything We Know

View List

Before Sheldon entered, Mary could be overheard asking George, “Are you sure your wife won’t come home?” And when Sheldon stumbled upon his parents’ love-making, George could be overheard moaning, “Oh, Helga!” Thereby it is unclear whether Sheldon knew it was Mary, or if he thought he’d just witnessed his father having sex with another woman — something the Big Bang spinoff has been teasing as a possibility since its Season 4 finale (more on that below).

It also didn’t appear as though Sheldon locked eyes with George, as we were told on Big Bang. And he didn’t run to his bedroom; he made a beeline for the front door.

“I never talked to my parents about what I saw that day,” our narrator told us. “But from then on I added extra knocks so people could get their pants on.”

When Young Sheldon first hinted at a possible extramarital affair between George and Brenda Sparks in Season 4, Episode 18, series co-creator Steve Molaro put out a statement. In it, he conceded that Adult Sheldon told some not-so-great stories about Dad on The Big Bang Theory — stories that were conceived before Molaro & Co. knew that Young Sheldon would exist.

“We try to honor those stories but also like to find unexpected ways for them to play out,” he said at the time. “These stories Adult Sheldon is telling us come from a new perspective — one he has gained after becoming a father himself.

“Sometimes life gets complicated,” Molaro remarked, “but we’re excited to explore these new chapters in the lives of the Coopers.”

Before anything could happen between George and Brenda, George had a heart attack in Young Sheldon‘s Season 5 premiere. Then in Season 6, Episode 14, when Brenda denied giving Mary’s husband a heart attack, he went and implied that she gave him “something” that night.

“I think you can read into it any way you want,” fellow EP Steve Holland told TVLine in March 2023. “I think it’s playful banter, but there’s definitely another layer there.”

Ultimately, the Powers That Be have decided to sidestep George’s infidelity. Holland, however, previously confirmed that Season 7 will incorporate Dad’s death.

“I don’t want to say what you will or won’t see, but things will get addressed,” the EP said in February. “We are not beholden to every joke that was ever made on The Big Bang Theory, but we do feel beholden to the larger canon and the larger events that shape Sheldon’s life. We want to honor those.

“That is a thing that happens in Sheldon’s life,” he continued. “This is the same character [from Big Bang]. We are living in the same universe as Big Bang and that sort of world building is important. Big things that [Adult Sheldon said] happened in his life without a doubt happened.”

Everything, that seems, except for George cheating on Mary.

TVLine previously polled readers, asking if they wanted Young Sheldon to abide by Big Bang canon and write to Sheldon walking in on his father with another woman. In the end, 68% of those who took our poll answered “Yes.”

What did you think of Young Sheldon’s decision to reframe why Sheldon knocks three times? Let us know in Comments.

Jim Parsons and Mayim Bialik return for 'Young Sheldon' series finale
Jim Parsons and Mayim Bialik return for 'Young Sheldon' series finale

Big Bang Reunion in Young Sheldon Finale

View List

Best of TVLine

Get more from Follow us on Twitter, Facebook, Newsletter