Investment Bang Edit Meaning

1.

when you link a girl who isn't particularly hot, at the moment, because you can tell she will be hot in a couple of years, because then you can 'cash in' on the investment when she's fucking buff as fuck

or in short

the act of securing sex with a member of the opposite sex who shows potential to be very attractive in future years with a view to securing future action when 'the chedder has matured'

dude....your sister requires an investment bang

See investment, bang, hot, future