Where's the story in which the Buddha praised a non-returner for keeping the knowledge of his attainment private?
"I hope, sir, that there were no white-clad householders there."

"No, friend, there were no white-clad householders there."

"It's good, sir, that there were no white-clad householders there."

http://www.accesstoinsight.org/tipitaka/an/an08/an08.023.than.html