When a man in a fivesome with one girl goes and shares one of her holes with another man. Double Oral, double anal or double vaginal sex.
Based on the mathmatics principle
Last night me, larry, jim, and bob were fucking lucy. Fucking bob instead of waiting his turn pigeonholed with larry and got his ass beat.
to put something into a drawer/box and forget about it for a long term.
to have unfair idea of what type sb or sth is.
That reports were only partly implemented or worse still, just pigeonholed.
He's a musician who can't be conveniently pigeonholed.