Rebecca is introduced when she and Bert arrive at Apartment 4A.
She is a stunning blonde who is a failed actress who has become a personal trainer. She's much younger than Bert. Penny asks if Rebecca has dates a scientist before because she was thinking of starting a support group. Rebecca says she dated a Scientologist. Sheldon quips Bert is copying Lenny. We find out they met online. Raj remarks he had not much success online. Bert says he only got success when he mentioned his $600 thousand grant. Sheldon gets sent out by Amy when he speaks inappropriately. Rebecca comes back and says if she'd done something wrong and Leonard just says it's just normal Sheldon. Rebecca goes to the toilet. Sheldon makes another comment, gets sent out again but Amy calls him back when Bec makes her suspicious again. It was all very funny but can't remember the lines. When Bert leaves, Sheldon compares them to Lenny - Bert's money and his groveling to get the girl and Leonard says it's completely different - Bert's money will run out but he can beg till he dies. Penny quips - all that and he's shorter than me.
Back at cafeteria next day, Sheldon tells a joke about Feynman, Einstein and Schrodinger. Raj and Leonard react slowly but eventually love. Bert comes in. He is worried about what everyone said about being used. He says something about the relationship that Sheldon thinks is funny and tells Leonard it's his turn to tell a joke.
Bert turns up at the apartment to tell them he broke it off. Raj starts saying he did the right thing, comparing him to his story which gets depressing and says maybe someone else should speak. Amy is glad but Bert is upset she convinced him. Sheldon has a go at her and she says to raise your hand for permission to speak. Penny tells Bert he should be looking for someone who likes him for who he is not what he has. Sheldon raises his hand and Penny makes the mistake of letting him speak because he delivers one of his trademark Lenny insults and Leonard just looks up at her and says don't look at me you gave him permission. Bert then leaves saying he might buy Bec a jet ski to get her back. Then there's a Fun with Flags retrospective retrospective and a call comes through and it's Bert saying it worked he got her back.