We all remember it: that first sleepover with a friend, when you'd get to play football until it was pitch black, then retire to watch films all night whilst eating nothing but biscuits and crisps.
And then you got there and discovered an awful, hideous truth: their family was really weird.
And all you could think was 'how long is it until I get back to my nice, warm, normal family? I was wrong to ever criticise you mum and dad, and I never want to leave home again.'
Well, you're certainly not alone, as this incredible Reddit thread entitled 'What's the creepiest thing that you've seen other families do that they accept as totally normal?' shows.
As you can imagine, there's some absolute gold in there - we've picked the best and weirdest below for you to either point and laugh at or be utterly terrified by.