The puzzled expression on the craggy features of our Corsican wildlife expert tells me that 'I've lost my yellow sister', doesn't make any sense to him, and what's more - the exaggerated Gallic shrug and receding back pointedly add - I am confusing him with someone who gives a merde.
Which leaves me both embarrassed by my schoolboy French and still short one younger sister, who has either wandered off into the sweet-scented, shrubby undergrowth, through which our coastal path is meandering, or plunged off the cliffs into the blue Mediterranean, a hundred feet below.
I'm betting the former but can't rule out the latter, which is why I'm willing to endure the contempt of rugged, manly Frenchmen. Sis has a habit of wandering off without saying where she’s going or why, although since it’s been a long walk already, the reason is fairly obvious, and confirmed five minutes later when she emerges from the bush behind us with the nonchalant stroll and pained expression of someone who's been searching for a good spot and failed to find it.
‘Tricky, was it?’ I ask her.
‘Very,’ she says, tight-lipped.
'My turn,' I say. 'Carry on and I'll catch up with you and the rest of the gang.'
'Be very careful,' she says. 'Some of the spikes on these plants are like crocodiles' teeth.'
'Are you OK?' she asks me, a few minutes later, as I rejoin her at the brow of a hill, where we get our first sight of the golden sands and blue-green sea of Plage de la Terre Sacrée.
'Barely,' I say, forestalling the concern beginning to appear on her face with a quick shake of the head.
'Did you know,' she says, taking the hint, 'that this rough undergrowth you get all over Corsica is called the maquis?'
‘Why would spiky undergrowth be named after the World War II French resistance?' I ask.
‘Other way round,’ she says, having researched well for this holiday, on which she’s finally persuaded me to accompany her.
'You get this stuff in the south of France, as well as here in Corsica,' she continues. 'It's ideal for hiding resistance fighters. That's why they came to be called after the terrain that concealed them.
'The name stuck because they - like the plants of the maquis - were tough, hardy and resourceful.'
‘And because nobody pissed on them?’ I suggest.
She tut-tuts, shakes her head and walks away. I’m getting a lot of scornful backs today. But I don’t care.
Blue skies and warm sunshine are beginning to ease the pain in my heart. The new pain in the nether regions might take a little longer.