▁the ▁flower ' s ▁small , ▁thin ▁pet als . ▁Although ▁now ad ays ▁usage ▁is ▁mostly ▁common ▁amongst ▁Chinese ▁net iz ens , ▁the ▁eu ph em ism ▁has ▁existed ▁in ▁Chinese ▁literature ▁from ▁much ▁earlier . ▁▁ ▁() ▁- ▁anal ▁or ifice , ▁as sh ole ▁▁ ▁() ▁- ▁an us ▁( med ical ▁term ), ▁literally ▁" door ▁of ▁an us ". ▁▁ ▁() ▁- ▁an us . ▁literally ▁" back ▁yard ". ▁ ▁M ast urb ation ▁Male ▁m ast urb ation , ▁at ▁least , ▁has ▁several ▁vul gar ▁expressions , ▁in ▁addition ▁to ▁two ▁formal / s cient ific ▁ones ▁that ▁refer ▁to ▁both ▁male ▁and ▁female ▁m ast urb ation ▁( ▁ ▁and ▁▁ ): ▁▁▁ ▁() ▁= ▁male ▁m ast urb ation ▁( lit . ▁" f iring ▁a ▁hand gun ") ▁▁ ▁() ▁= ▁male ▁m ast urb ation ▁( lit . ▁" h itting ▁an ▁air plane "). ▁A ▁term ▁which ▁origin ated ▁from ▁the ▁C anton ese ▁language . ▁▁ ▁() ▁= ▁male ▁m ast urb ation ▁( lit . ▁" stroke ▁the ▁pipe ") ▁▁ ▁() ▁= ▁male ▁m ast urb ation , ▁also ▁" st ro king ▁the ▁pipe " ▁▁ ▁() ▁= ▁male ▁m ast urb ation ▁( lit ., ▁" play ▁with ▁little ▁brother ") ▁▁ ▁() ▁= ▁male ▁m ast urb ation ▁( lit . ▁" five ▁be ating ▁one ") ▁▁ ▁() ▁= ▁male ▁m ast urb ation ▁( lit . ▁" to ▁see ▁[ vis