Originally Posted by xliioper

While the airlines certainly have to pay for their pax to enter third-party clubs (hence DL cutting access to them unless in D1), no one here likely knows how it works with fellow partner clubs. It may be as simple as Skyteam contractual obligations and DL simply can't change the access rules for partner elites to access Sky Clubs (even if they'd like to), but is free to do so for it's own elites.