Well... It's when you have two fingers in the girl (Foolin around) anyways, they are your two middle fingers. You have the out two fingers sprung back and ready and at the right moment driscoll surprise or BAM! is called and bam all 4 fingers are in.
Doin a chick in the backseat of her car and BAM! Driscol SUPRISE!
When fingering a girl with the middle and ring finger, the other 2 fingers are bent at the middle knuckle. You then yell "DRISCOLL SURPRISE" accompanied by "BAM"(optional) and shoot your other 2 fingers into her as well.