To fight in a superheroic or crazy way.
Errol Flynn was the star of various adventure movies like robin hood, captain blood, etc.
Joey was getting jumped by a gang but suddenly went all Errol Flynn and kicked their ass!
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