when a girl's gag reflex causes her to vomit (often thru the nose) while attemting to "deep throat" a guy during a blowjob; occurs when the chic either (a) underestimates the size of the dick she's sucking; or (b) overestimates her oral prowess.
blowjob, deep throat
Things were going great with that hottie last night, until she gave me a shelley dog in the car. What a mess, but i finished anyway!!