If you had a babysitter until 1 or 2am, would you expect / be happy for them to kip on the sofa? I'd never have thought to do it - seemed a bit CF, but my mum seemed to think I ought to, and said she'd have been happy for a babysitter to do it if they were there past 11pm or so
(Context - A-Level student babysitting on Fridays / Saturdays)