Disclaimer: I don't own any of these characters, just borrowing them.
Penny walked into Apartment 4A without knocking. She noticed Leonard and Sheldon were both in the kitchen. Leonard was putting on the coffee maker and he had his back to Penny, Sheldon too had his back to Penny, neither had noticed she had entered the apartment.
Sheldon was sitting on the kitchen island, when did Sheldon sit on the kitchen island? She noticed he was also wearing jeans, and a yellow checked shirt, what happened to the layered shirts, and jeans, where did he get those from? He appeared to be chatting with Leonard, laughing and the most unusual sight was that he was drinking a beer.
It was then that they both looked around at Penny.
"Oh hey Penny," Leonard said "I don't think you've met Sheldon's older brother, George."
George jumped off the kitchen island and walked over towards Penny. She looked at him, the resemblance was startling.
"It's freaky isn't it?" Leonard said "It's like an improved Sheldon, you know one that is nice."
"Hi Penny, heard a lot about you." George offered his hand. His Texan drawl was a lot more pronounced than Sheldon's but they had very similar voices. "It's good to finally meet you."
"Hi," was all Penny could stammer out, she just kept looking at him. He was just a slightly older version of Sheldon, but also without the tics and it appeared no wack-a-doodle personality.
"George is just staying for a couple of days, he needed me to sign some papers." Sheldon had walked into the kitchen, he appeared to have come from either the bathroom or his bedroom. "People say we look alike, but I don't see it myself."
Penny looked from Sheldon to George and back again. "Sheldon, you look exactly the same." she replied.
Sheldon rolled his eyes and walked over to sit in his spot.
"So Shelly, what you got planned for us to do hey?" George asked.
"Planned? I have nothing planned." Sheldon replied to his older brother.
"Oh come on Shelly, I've never been to LA before, I need a tour guide."
"I am a very busy man George, I can't just give up my work to become tour guide for you."
Penny looked up at George and said. "I've got tomorrow off work, if you like we could go do some stuff."
"Oh thank you Penny, that would be delightful."