That's the first time I ever heard that explanation (open legs) -the most common is it is a sign of defiance from English archers to French who it was said woul

That's the first time I ever heard that explanation (open legs) -the most common is it is a sign of defiance from English archers to French who it was said would cut off the two right fingers from any captured archers. That is pretty rigorously debunked but is still popular I think ultimately it's an arbitrary rude gesture that became popular and stuck. As my seven year old is delighted to learn, it's rude enough to shock but nowhere near as rude as a middle finger.