when the girl completely doesnt expect it, and shes just walking down the hall or something, and the dude just pokes around the corner and cums on her like its a squirt gun fight
'damn that girl was walking to class, until she got supersoaked by that guy leaning out the third floorwindow'
notice, the motion of your hands when you pump up a supersoaker squirt gun are the same as when giving a hand job. therefore, to supersoak is to give a handjob.