To ejaculate during an "imtimate" IM conversation with a stranger and block them immediately afterwards.
Girl - That Bastard just did a cum and run on me, i'll never get to know his asl.
by Jim Bob Ironing Board Scarface Vercetti November 13, 2007
to cum on a girls face after intercourse, and quickly grab your things, run out, and never return again.
Last night I gave Jodie a mean dirty harry, and pulled a cum and run. I couldn't find my underwear though, but it was a feasible sacrifice.
by ChrisCash April 18, 2011