Flew DEN-ORD on a three class 777...configured with only 10 F Suites and a separate crew quarters. The flight attendant in F was excellent and I asked her why we couldn't use the F lav next to the cockpit. She said the pilot informed her not to let anyone past the curtain. She found this to be terrible and was really upset about it.

But when you fly on the 777 configured with both F lavs next to the cockpit and the crew rest is one of the F suites, I don't think the captain has any choice but to keep both F lavs open.

Seems like a strange way to increase perceived security to me.