When an
individual of the male persuasion in an institutional circumstance (i.e. work, school, etc.) becomes
sexually aroused, due to thoughts of past sexual exploits; the subsequent tightening of the groin area, due to the constriction of pants upon the hardened member, produces a penile-angular shift, which is almost perfectly
horizontal in form, and points towards either the left or right. Thus the moniker, Side-Pipe.