Shauna acted hurt that Ethan wasn’t taking her to the Prom.
There was a moment when he tottered; after all, the Pool thing started at 2 pm. They could go to Stan’s pool, spend two hours or so, then go home. They’d have plenty of time to get ready and reach the Prom at 7.
However, how Shauna made it into a situation, barking; “All my life I dreamed of going to my High School Prom!”
Ethan was cemented into the anti-prom camp and he replied;
“Shauna, you go. I’m sure you can find a date, or go with your friends…I’m not going…”
And he walked off. He walked off, as he did the annoyance the anger faded. He was feeling good.
After all, if she never though to discuss anything with him, if she never felt an obligation to explain events, why should he break the pattern?