My sisters and I frequently conclude a tale or fact of dubious merits to each other with the line 'But don't tell Mum'.
It doesn't matter that we are all in our 30's and 40's - mother's approval still counts.
It's not as if we're out dancing on tables and failing to come home (well not often), or ingesting various forms of narcotics and failing to remember our own name (well not often)...it's a far tamer than that.
Often it's to do with money.
'Do you like my new boots? They were a bit too expensive but I love them. €150. Yeah I know. Don't tell Mum.'
Or to do with being irresponsible perhaps...
'I know I should be wearing my glasses driving but I broke them five years ago, and anyway I never liked them. Don't tell Mum'
Or it may be that one of us has had some unorthodox anti-aging technique applied or some questionable waxing done. But whatever you do - don't tell Mum.
A big one is one of us taking on too much when she knows we are too busy as it is.
'I just bought a puppy. Yes I do know it's only 2 weeks until Christmas and I haven't got any shopping done yet. DO. NOT. TELL. MUM.'
But none of us would be that stupid now would we? Besides - we'd never get away with it.