A term used in the form of "emotionally" connecting with somebody new.
Derived from the construction toy/puzzle known as "k'nex" where in which pieces of plastic are connected together to make buildings, cars etc...
For example,
Two guys are in a bar, one guy goes over to a girl and they talk for half an hour, gaining her phone number. The other guy then nudges him and says
The hypothetical man (often a sinistercharacter who decided not to go to boot camp) that is doing your girlfriend/wife while you are on deployment overseas.
Ain't no use in goin home,
Jody's got your girl and gone.
Ain't no use in goin back,
Jody's got your Cadillac,
Ain't no use in feeling blue,
Jody's took your checkbook too.