I'll bet he keeps Corinne until close to the end
He just wants to bang her. There is no chance he wants her as a wife, but he wants to take what she's offering and then choose someone like Vanessa or Rachel.
The fact that she's still there after her inappropriate behavior makes me lose respect for Nick. I know the producers want to keep some people there too, but he seems to be enjoying her antics way too much. He actually licked whipped cream off her boob. Gross.