What's the Name of That Book??? discussion

I'm a woman from Spain who found you by chance while searching through readers' forums, because I have no idea where else to look—nobody seems to be able to find this book. I read a book about 30 years ago whose title I can’t remember, and I barely recall the story itself. It’s come back to my mind and I’d love to read it again if I ever manage to find it. Maybe you can help me—here’s what I remember: it was about the story of a grandfather and his grandson, who had very little relationship with each other. For the grandson’s 18th birthday, the grandfather gives him private French lessons as a gift. The grandson doesn’t understand why he’s getting this present, which he doesn’t like at all, but little by little he begins to understand and they develop a beautiful relationship. I remember very little more, except that the grandfather had lived in exile in France, and that he takes his grandson to a brothel one night. The grandson eventually goes to Paris to recall what his grandfather used to tell him, and that’s about all I remember. I know I really liked the book back then and I’d love to find it again.