The news that Marshall and Lily have a positive reading on their pregnancy test has a profound effect on the gang. Meanwhile, Robin must choose between two very different jobs, Barney is pulled between donating to charity or buying a diamond suit, and Marshall and Lily are thrown into a panic over their impending parenthood.
Lily can't stop talking about babies and it's putting a strain on her relationship with Robin, while Barney finds a copy of the Canadian children's programme `Space Teens' starring Robin's alter-ego `Robin Sparkles'.
While Barney prepares for his wedding to a mystery bride, he and Ted reminisce about Punchy's wedding. Meanwhile, Robin considers telling Barney she has feelings for him.
Robin rekindles a spark with Simon. Robin tells the gang how Simon had dumped her as a teenager for a girl whose parents had installed a swimming pool. Robin's friends tell her that she is more successful than Simon and that she shouldn't go out with him. Robin, however, accepts a date with him. Later, when Simon ditches Robin, she is consoled by Barney.