ok. . . so you and your lady for the evening have been raving it up doing drugs, drinking and anything else that makes your sweat stink in a sweaty night club for about 8 hours.
you finally make it to bed (or wherever it is that takes your fancy) and start getting busy.
only to find your partners genital area stinks of dead fish in cheese sauce. an you'd sooner gag than get lickin and suckin.
we've all been there.
A trip to a grocery store, convenience store, or gas station for the sole purpose of buying an excessive amount of junk food and sugary drinks, usually with friends. A chud run often happens late at night and ends with everyone involved hating themselves afterwards.