Aliasing flexible → contortion
Link to alias

Reason:

Honestly I don't care in which direction this goes (there's contortionist aliased to contortion so I can't suggest the other way around), but I'm just generally dubious that these two tags are anywhere as clearcut as seems at first glance.

Don't know if anyone else shares my opinion but I consider contortion(ist) to be a much more extreme form of flexible; as in flexible being something that wouldn't be very surprising to see, while contortion makes you go "woah, I can't believe you can really do that."

However I can see your point in the two getting mixed up.

I understand the principle, but I don't see all that much difference and a lot of stuff I see in "flexible" I'll see done by the average contortionist too.

I would vote for the other way around personally, either an alias or an implication.

I don't know if an implication is worth it, but it's another option.

Flipped the alias and approved.

Also approved contortionist -> flexible.