In Ring Up, Ted meets and starts seeing a girl who turns out to be just slightly younger than 21. While he finds her really attractive, the difference in their age means he has trouble connecting with her. When he is about to give up and end things with her, Barney convinces him to give it a shot, which will allow Barney to live vicariously through Ted now that Barney is engaged to Robin. Ted finally gives in when he realizes she likes Star Wars. After their one-night stand, however, Barney finds out that she is actually Carly, his half-sister. Barney attempts to marry Ted and Carly, and mentions that he finds the idea of a one-night stand "cheap, meaningless and disgusting". She also likes older men.