McMurphy ask Billy Bibbit why he chooses to stay in the hospital when he could be outside driving a convertible and romancing pretty girls, what does Billy say?

Billy's reply, from the text:

"You think I wuh-wuh-want to stay in here? You think I wouldn't like a con-con-vertible and a guh-guh-girl friend? But did you ever have people l-l-laughing at you? No, because you're so b-big and so tough! Well, I'm not big and tough. Neither is Harding. Neither is F-Fredrickson. Neither is Suh-Sefelt. Oh--oh, you--you t-talk like we stayed in here because we liked it! Oh--it's not use..."