Sally was Bret's ex-girlfriend and Jemaine's love interest in the comedy series (Flight of the Conchords).
Jemaine saw Sally at a friend's party and was instantly smitten. He managed to impress her with his dance moves and invited her back to his place. Things came to a halt when Sally found out that Jemaine lived with Bret.
The next time Jemaine sees Sally, she tells him she'd date him seriously if he had his own apartment. Jemaine moves out, which causes friction between him and Bret. Sally eventually tells both Bret and Jemaine that she's engaged to an Australian.
Bret dated Sally for about 6 months before the series began. When Jemaine moves out so he can court her, Bret's lingering feelings for Sally begin to resurface to the detriment of his current relationship. Sally eventually tells both Bret and Jemaine that she's engaged to an Australian.