Who would guess that Penny and Leonard's Valentine's day wouldn't go as planned on The Big Bang Theory? "The Tangilble Affection of Proof" is the 16th episode of the show's sixth season.

The Big Bang Theory Season 6 Episode 16 Quotes

Well, this time is going to be different because I'm a like a romance ninja. You don't see it coming and then BAM. Romance, watch out, hearts, kisses, love, ewww wah.


Penny: No, I said "Oh my God, I think that old guy's choking" and one of the busboy's Heimlich'd him.
Leonard: You're a hero...
Penny: Yeah ... that was the point of the story.