Shandhangle
The specific act of when two people engage in sexual intercourse, one of the two people being your best friend. The other being a girl or guy you are not too familiar with, but not being a total stranger either.
(Friend 1)Where is Alex?(Friend 2) Oh, he is having a shandhangle fest with that girl Nicole he is always hooking up with, have you met her? (Friend 1)Maybe once or twice.