Try to stick with one phrase - goodnight, time to sleep, etc - getting into a chat does not help here at all. In fact saying "goodnight time to sleep" bugged my LO2 hugely as she did not like being told what to do! So when she got to the "mammy, mammy" stage and I was outside the room, I would say something very simple like "I'm here", "I can hear you", and just "yes" very calmly. HTH