A competition between guys for a bet which involves you go home to the wife, getting her in the sack and hit it doggy style. In the middle of the session, whilst still in the same position you call your wife/missus a different name to which she will hopefully react badly to.... and you job is to try and stay inserted! The winner of the competition is who can hang on to the wife the longest!
(can also try the harder version by calling the wife a blokes name, she'll buck like a good'un!)
<Adam>Fancy a good shagging then wife? I got an itch for it doggy style
<Jane>Go on then
<Adam>oh yeah, oh yeah.... oh Sally your ass is sweet
<jane> What the fuck?!?! Who the cunt is Sally? get off me you shit.. (struggles to get away)
<Adam> counts the seconds
~~penetration is lost~~
<Adam>12 seconds, result!
(you may want to explain to the wife what has happened!)