My personal favourite was the mum of a kid in year 7 who emailed me late one night just before the trip: 'how much pocket money should Tom take?'
I taught Tom period 1 next day. So having checked my emails in registration, Tom arrives p.1. I collared him at end of lesson having dismissed everyone else. 'Tom, your mum has asked about pocket money for the trip. Can you tell her it's up to her but about £20 is average? You'll just need it for the gift shop if you want to buy a souvenir, & maybe a snack at the services, although you'll get a packed lunch so you don't actually need cash really.'
Tom: 'cheers miss, thanks, I'll let her know.'
I emailed mum at lunchtime to explain all this (which was already in the info booklet I'd given out to every parent, but whatever).
Five minutes later, I get a call from the office: 'Tom Smith's mum is here. Says she's sent you a really important email & you haven't replied. She's insisting you come down to the office & explain'
Me: 'sorry I can't! I'm in a meeting this lunch hour, with another parent, which I'm already late for. Can you ask her to check her email as I have replied?'
No response from Tom's mum.
Until she rocked up half an hour late, at midnight, to collect Tom when we returned from the trip shouting 'where is Mrs Crowy? She didn't meet me before this trip to tell me how much pocket money Tom should take! I gave him £50 & he's spent it on crap! I'm NEVER letting Mrs Crowy take Tom on a trip again!'
The sad thing was, Tom was a sweetie. Otherwise never taking him on a trip again would have been fine by me....