The Savage Wedding by Yann Queffélec.
Nicole is the daughter of the village baker somewhere in provincial France. She's nearly fourteen, looks eighteen, and has been conducting a tentative romance with Will, an American GI at the local army base.
That's all very lovely and innocent. Trouble is, the base is being closed down and Will is being shipped back to the USA, so he hatches a plan to rapidly (i.e. in a single night) accelerate his courtship of Nicole up to and beyond the point of physical penetration, forcibly if necessary. Needless to say it turns out force very much is necessary, and lots of it, especially when Will invites his mates Aldo and Sam to join in.
So the GIs swan off back home leaving Nicole brutalised, traumatised and, it transpires, pregnant. Despite her best efforts to induce a miscarriage with various quack herbal concoctions and a rusty spoon handle the baby (a boy, Ludovic) turns up robustly healthy, at which point Nicole and her parents banish him to the attic for several years, so as not to have to gaze upon the cause of the family's shame.
Scarcely surprisingly as a result of these non-standard parenting techniques Ludo turns out to be A Bit Odd, though clearly not mentally deficient in the way that his family insist that he is, largely for their own self-justifying convenience. Eventually Nicole embarks on a marriage of convenience with an older man, Micho, and Ludo moves into a bigger house with Nicole, Micho and Micho's older son Tatav.
So things seem to be looking up. Needless to say a spanner soon gets lobbed into the works: not only is Nicole extremely unreceptive to Micho in the bedroom, not surprisingly, she's also cold and dismissive of Ludo, since looking at him requires her to relive her ordeal every day. Eventually she persuades Micho (with the persuasive suggestion that with Ludo gone things might get a bit spicier in the boudoir department) to ship Ludo off to the children's home/mental asylum run by Micho's cousin Mademoiselle Rakoff.
There then follows a somewhat One Flew Over The Cuckoo's Nest interlude wherein Ludo is obliged to conform to the stultifying institutional regime, punished for minor non-compliances and generally encouraged to act like a mindless sedated vegetable, with visits from his family being the only ray of sunshine on the horizon. These visits are disappointingly intermittent, though, and always involve Micho (and occasionally Tatav), never Nicole. After a visit where Micho alludes darkly to some marital discord between him and Nicole, even these visits dry up and Ludo is forced to conclude that he's been abandoned.
There being no handy giant marble washstands to hurl through a window (and with his institution operating a slightly laxer security regime anyway) Ludo simply hops the fence one night and sets off to seek his fortune. He winds up in the coastal village of Le Forge, and, wandering off to the beach, discovers the beached wreck of a ship, the Sanaga, which he makes his home. It's not exactly luxurious, but after forced co-existence with Tatav and forced communal living at the institution the solitude is just what Ludo needs, and with occasional jaunts into the village for supplies and occasional interactions with the assorted types who frequent the beach he's reasonably happy, in his own way.
Further spanners are thrown, though, inevitably: it turns out that the wreck is only a shortish walk down the beach from Ludo's old family home, which sets him thinking about his mother again. He also learns that the hulk of the Sanaga is due to be cut up for scrap, and that questions have been asked in the village connecting an escaped lunatic from a local institution with the mysterious young man who's been living on the wreck.
Then, unexpectedly, Nicole turns up at the wreck. Has she come to finally declare her maternal love for her son, the only thing he's ever really wanted out of life? Answer: no, she's been sent by the authorities to lure Ludo out to a place where they can grab him, tranquilise his ass and drag him back to the asylum. But Ludo doesn't know that: all he knows is that providence has sent him an opportunity to resolve his feelings for his mother and he's going to seize it with both hands if it's the last thing he does. Or, indeed, that either of them do.
You'll see that this is not exactly a barrel of laughs, despite my occasional levity above. Given the subject matter it'd be easy for it to tip over the edge into lurid melodrama, but Queffélec's spare, ruthless prose style prevents any of that from happening. The central message is, basically, they fuck you up, your Mum and Dad. Obviously you feel sympathy for Ludo, whose life was irredeemably fucked up before he was old enough to know anything about it, but you also feel for Nicole - despite her being the principal agent of Ludo's upfuckery she was fucked up in her turn by her experiences at the hands of Will and his mates, and subsequently by the wholly unsympathetic treatment she got from her parents. Despite the grimness of the theme and the evident impossibility pretty early on of it ending well for anyone I enjoyed it very much. Queffélec is a better writer than, for instance, Michel Houellebecq, for all of Houellebecq's higher profile and notoriety.
The Savage Wedding won the Prix Goncourt in 1985 - this is one of the grands fromages as far as French literary prizes go, but I think this is the only winner that I've ever read. It was also filmed as The Cruel Embrace in 1987.