Step-cousin of the Dirty Sanchez, the Errol Flynn also involves jamming a finger in the girl's ass while doing her doggy style. You then pull her hair back to give the Errol Flynn slicked-back swashbuckler look and apply a pencil-thin brown mustache to her upper lip.
Unlike a Dirty Sanchez, the Errol Flynn involves use of the pinky finger and not a thumb.
It was like the Adventures of Robin Hood last night with your sister. With that pencil-thin brown mustache, she looked just like Errol Flynn