Why would pilots get special cups? This Reddit post shows a picture of a disposable cup that is labeled specifically for use by pilots only:



Is that seriously a thing? If so, why? There's some explanation in that discussion thread about fitting cup holders more tightly, but it doesn't sound like a plausible explanation to me, since the cup holder should be designed to hold the cup properly, not the other way around.
The answer is pretty simple...

It is because those cups have matching lids that won't fit the passenger cups. Lids are used on the flight deck to keep the liquid inside from spilling on the (ever increasing) electronics, especially those located in the center console between the pilots (which house the radios in a lot of airplanes). 

So some airlines have made a policy of any cup going into the cockpit must have a lid, and these cups specifically have lids.