6-4

[Little_Girl]

64 impala, the best car

[Mark Zuckerberg]

a 1964 Chevorlett impala, populerized by Eric lynn Wright aka Eazy-E, the Ragtop is a Chevy 6-4 ss convertable soft top

[Cami]

Your 6-4, pronounced, Six, four is the person you want to spend forever with. He/She is the person you have the most sexual [chemistry] with and wouldnt mind licking their body wherever they tell you to [lick it]. They are the person you want to [make-out] with after you each have oral sex all over each other.
Your 6-4 is the [purest] sexual connection possible. You can come while talking to your 6-4 on the phone without touching yourself.
Your 6-4 is the embodiment of what you find sexy. Your 6-4 makes you want to fuck every time you see them or hear their voice and see them smile.
Your 6-4 can do no wrong.
The sexual chemistry you have with your 6-4 is caused by the never-ending amazing line of conversation and communication you have with that person, especially when it comes to discussing how to please each other sexually. But also, just normal everyday perfectly effortless conversations which ultimately draw you to your 6-4 uncontrollably, even after fighting or [disappointing] each other.
Its derived from the second basemen and [shortstop] chemistry in baseball. 6 being the shortstop and 4 the second basemen.