‘She’s not leaving me!’ Tom’s words suddenly leaned down over Gatsby. ‘Certainly not for a common swindler who’d have to steal the ring he put on her finger.’
‘I won’t stand this!’ cried Daisy. ‘Oh, please let’s get out.’

– F. Scott Fitzgerald

The Great Gatsby. Chapter 7, Tom opposes Daisy’s relationship with Gatsby. Gatsby is not fit to marry Daisy because of his social class, he believes. He is not part of the upper class.