Is when the male partner's balls repeatedly smack against the female partner's vagina while perfoming anal sex.
Martha really likes the double doppler effect when I am doing her up the butt.
by Frances Wates June 19, 2006
when both male testicles are placed in the female anus
I gave Sherri the ol' double doppler last night and my balls barely fit!
by dopplehoffers February 23, 2011