While in the famed doggy style position, just before the man is about to blow his load, he stretches back with his thumbs (of doom) pointing up in the positive gesture position, he shouts "thumbs of doom" and just as he blows off he sticks his thumbs up her ass.
by B-team April 12, 2008
Mike used all of his accumulated video game skill when he went home drunk with a girl and gave her the THUMB OF DOOM
by Marc Pearson January 24, 2004