The "ninety-degree cousin" to "collateral", this term refers to the promise of intimacy (i.e., a "longitudinal" bodily-position) to someone in case you are unable to pay back a loan that you're asking him for.
One should always be wary of an offer of collongitudinal, since there is no guarantee that da gal will indeed "deliver da goods" if da time comes for said submission, any more than she can truly guarantee that she will pay back da loan, either.
by QuacksO December 10, 2018