CBS

Season 6: Episode 16 - The Tangible Affection Proof

The Tangible Affection Proof: It's Valentine's Day and Leonard wants to give Penny a night full of fun and romance, despite her not being the biggest fan of the holiday. He takes her to a fancy restaurant with Bernadette and Wolowitz, but things take a turn for the worse when Penny sees her ex-boyfriend propose to the girl he cheated on her with. Thinking quickly, Leonard tries to propose to Penny, but she doesn't want to hear it. After arguing with Leonard and leaving the restaurant, they make up when Leonard vows to never to propose again, instead letting Penny be the once to propose if and when the time is right. Meanwhile, Amy tells Sheldon that she wants to celebrate Valentine's Day, and that she's found the perfect gift for him. Distressed and annoyed at being forced to celebrate a holiday he hates, Sheldon tells his assistant, Alex, to find the perfect gift for Amy. When Alex's suggestions don't satisfy him, he winds up making Amy his emergency contact at work, which she loves. Amy, in return, gives Sheldon nothing, which is exactly what he wanted, as well. Since Koothrappalli and Stuart are without Valentines, they throw a singles' party at the comic book store and it turns out to be a success.