Marshall and Lily are about to get hot and heavy, when Marshall runs to the bathroom and remembers what his dad told him if he wants to avoid a baby girl: right before sex, he must eat pickled herring. He gobbles it down. Back at MacLaren's, Barney asks a girl to play with his imaginary friend, another one to play telephone, and one to change his wet pants. He tells Robin and Ted he can't pick up a girl while talking like a little boy. "Challenge forfeited." They really don't care, but he basically cries himself out the door. Ted tells Robin he's glad that's over, since he was creeped out by Barney talking like a little kid. Robin doesn't get why he likes it when Becky does. Ted says Becky makes him feel needed, which is nice and not a feeling guys get with Robin. Back in Marshall's bathroom, he continues following his dad's advice by grabbing a bowl of ice and dunking his "man sack" in there. He doesn't last long before screaming "Eriksen!" He remembers his dad's final advice to point Lily due north, then heads back in to ravish her.
Robin and Ted discuss how she didn't make him feel needed, because she took care of everything, including being the guy in bed and having a gun by the bed in case of a potential break-in. He admits it bothered him because it's nice to be needed. His BlackBerry beeps, and he says it's Becky, who's trapped in a revolving door. Robin's got the bill, so he takes off. Marshall gets back in bed, and Lily points out the cold and the smelly breath. Then he points her north and she puts it all together: "You're trying to make us have a boy!" He wonders how she knows, and she tries to play dumb before admitting (especially when he notices the lemons by the bed) that she's trying to make them have a girl. But it's only because all of her least favorite students have been boys. She says the internet told her to point south during sex, eat a lemon, and heat up her lady parts, which she did with a blow dryer just before Marshall ran back in. They debate whether boys or girls are better, using horror movies as their examples. When Lily brings up Chucky, Marshall gets scared.