When you're doing a chick in the ass and she gets diarrhea and it squirts out all over the place. Kind of like when you stick your thumb in the end of a hose nozzle and the water shoots out forcefully.
Rich: "So how was fuckin Lauren last night? I could hear it going down in the living room."
Adam: "Well it was good till I stuck it in her ass. Then i got the old Thumb in the Hose Nozzle action and spent the rest of the night cleaning up your leather couches."
The country boy woke up and found his date and wallet missing after a passionate night of love-making. "She said that she loved me, but I guess I just got HO-sed."
At one point just before ejaculation, the controller (read: the one holding the "cock") can choose to put a finger, thumb or round object posed just above, or to the side of, the urethra of the penis. Upon exiting the urethra tract, the semen contacts the finger, thumb or round object and because of the obstructed path from said object, the ejaculated semen sprays like a "dirty" hose. This can be a solo, partner, or group act.