'The Big Bang Theory' recap: A 'Young Sheldon' character arrives for the first time

"The Big Bang Theory" got a shot of the heart and family drama that's made its spinoff 'Young Sheldon" so popular in the last episode before Sheldon and Amy's big wedding.

The episode opens with Amy walking in on Sheldon in a heated argument with his mother on the phone. When he hangs up, he reveals that she’s not planning to come to their wedding if he doesn’t invite his older brother, George Jr. (Georgie).

Fans may remember Georgie from the spinoff “Young Sheldon,” where his adolescent self torments Sheldon almost every episode. This, however, is the first time that the flagship series has introduced him in the flesh. But before that, Sheldon has to deal with the fact that Amy is flummoxed by the fact that George wasn’t invited in the first place. She, along with his mom, insists he mend broken fences between them.

This proves to be difficult when Sheldon approaches Leonard the next day to inform him that George is ducking his calls. His voicemail is even set up with an insult to his little brother, just in case he calls. Sheldon is desperate to have his mother at the wedding, so when Leonard makes the mistake of asking what else he can do short of flying to Texas to talk to him, he quickly finds himself on a plane with no understanding of how he was manipulated into going.

Meanwhile, as the girls go over wedding gift bags for the big day at Bernadette’s, Howard comes downstairs to break the news that the kids have pink eye.This is incredibly unwelcomed news to Amy, who is a week away from getting married. Sadly, the next day Bernadette calls to mention that she, Howard and Raj contracted the illness and ask if Penny has as well. While she’s in the clear, Amy comes into frame livid with her right eye swollen shut.

In Texas, Sheldon and Leonard find themselves in front of one of George’s tire stores. It turns out, despite his half-witted nature, George opened up a very successful chain calling himself Dr. Tire, a moniker that irks Sheldon to no end.

He politely asks his brother, played by guest star Jerry O’Connell, if he’ll attend to which he receives a resounding “no.” Dejected the duo go back to their hotel where Leonard offers to try and talk to George when Sheldon starts considering getting married without his mother present.

Leonard arrives at the tire store to chat with George, who explains that he’s had enough with Sheldon’s neediness and ungrateful attitude. Leonard can relate, having babysat Sheldon for many years. However, it quickly becomes clear that his brother’s gripes run deeper. He reveals what many “Young Sheldon” fans already know, that every spare dime the Cooper clan had went to Sheldon’s education. George had to build his business from nothing and, despite his hard work, Sheldon is still their mother’s favorite.

Still, he’s able to bond with Leonard enough for him to get convinced to come back to the hotel to share all this with Sheldon in person. George explains to his brother that after their father died and Sheldon went off to college to spend all their money, it was up to him to take care of things as their sister, Missy, was just a teenager at the time and their mother was a wreck.

Sheldon doesn’t relent, noting that he talked to their mom all the time and that if something were wrong, she would have told him. George explains that she was protecting him, and admits that he did the same thing by keeping him in the dark about the family’s hardships. Just like that, a visibly shaken Sheldon gives an earnest apology to his brother and an even more ernest invitation to his wedding.

George accepts.

Meanwhile, after the gang back home learned that the pink eye scare is bacterial and likely to dissipate before the wedding, Raj finds himself in line at the pharmacy talking to a cute girl who also has pink eye. He’s desperate to not be the only single person at the wedding, and abruptly invites her to go with him just before the credits roll.

It seems there's nothing left now but the woman's answer and the big day will finally arrive.