The act of involuntarily and immediately regurgitating cum all over a man’s penis during or directly after orgasm while attempting to swallow
. This can happen from either a failed swallow or by the man’s penis being too deep (or being forced too deep) into the mouth of the person giving the blowjob.
Kate: I thought I had it, but when he started to cum he pushed in deeper and I couldn't hold it all and totally cumchucked back on his cock and bed.
Robin: Oh my God, was he pissed?
Kate: A little, but he was still in postcoital bliss
, so he was cool with it.