Simply scrawl the following in a bathroom stall, write it in wet cement, tattoo it on someone's forehead while they're sleeping:

   u=2∫as ds|u(0)=0
Hopefully, they will go ahead and figure out what you're saying:
   u=2∫as ds|u(0)=0
    =2(1/2 as2+c)|u(0)=0
    =as2+c|u(0)=0
         u(0)=0=a (0)2+c
              0=0+c
             ∴c=0
  ∴u=as2+0
    =as2

Your victim's self-esteem plummets as your message becomes clear:

u=ass
QED.