Many thanks to Jane Wickenden for the first sentence…
“Marmalade? I don’t know what you’re talking about.”
“Yes you do, Orlando – sticky stuff, full of orange peel – the sort of thing you have all over your face right now, despite the fact you swore there was none in the house.”
“Ah, well, you see I discovered it was simply an optical illusion and there was just the merest smidgeon lurking at the bottom.”
“Sounds like a Sherlock Holmes story,” Jonty snorted, “the Mystery of the Not Empty Jar.”
“More like ‘The Mystery of how I ended up with you’,” Orlando muttered, although he made sure he snaffled the last piece of marmalade laden toast.