Asim bin Muhammad reports from his father that a man said to Sayyiduna Abdullah bin Umar (may Allah be pleased with them both): We go in to the ruler and say things to him other than what we say in his absence. He said: We regarded this as hypocrisy.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قتال أهل البغي / 16661