When Maud and Geoffrey finally do meet again, she is repulsed by his appearance and conversation and appalled by her own apparent fickleness. But of course, she was never in love with him and is now viewing him for the first time without the blinders of her infatuation. Actually in love with George, Maud was always going to find Geoffrey unsatisfactory: his preoccupation with fatty foods merely made it easy for her... as did the revelation that he'd been consorting with an actress at the theater. This in itself would have killed Maud's feelings for him- if any had still lingered- as it would be totally impossible to take any man seriously who is capable of referring to himself as "Pootles".
What horrifies Maud almost as much as the sight of Geoffrey inhaling pats of butter is the sudden realization that her Aunt Caroline was right. Throughout the narrative, Lady Caroline has been seen as the baddie- keeping her niece cooped up at the castle and doing her best to keep Maud and Geoffrey apart. She has insisted from the beginning that it was just a youthful infatuation on Maud's part, and as it turns out, that's exactly what it was. Snobbish and domineering as Caroline indubitably is, in this case, she was also correct.