The teenage act of using your thumb as a hole guide for your cock which is larger than she is used to. After slapping your fumbling dick in your palm, you gently insert your thumb into her pussy. Like Houdini you simply run your cock along your thumb, using it like a ruler or a guide, to direct and allow an easy and simple access’s to an otherwise unsatisfied pussy.
She was too tight for me, it was dark and I couldn’t even find her hole
properly. I heard Jimmy strolled in last night at the pub and after a few drinks he took her home. Apparently he used “the rule of thumb” his old
Man taught him. After a while the crafty fucker worked his huge knob to the hilt - and we didn’t see him for 3 days!