First heard on Rizzoli & Isles. Jane Rizzoli claims it means "Life Long Best Friends Forever" while she is canoodling her best friend (and obvious lesbian lover) Maura Isles in front of a nice ass red car. We all know it means "Lesbian Lovers Best Friends Forever". But Jane can say what she wants. It's all cool.
Jane and Maura are clearly LLBFFs, as seen in basically every episode, where they engage in hardcore eye sex and display public affection more than needed.