Complex sentence: The two climb into the front seats, and Dean gives Rory a final surprise, telling her that he loves her, but when she looks shocked and does not respond, he realizes it was the wrong thing to say.
Split into simpler sentences: The two climb into the front seats, and Dean gives Rory a final surprise, telling her that he loves her. But when she looks shocked and does not respond, he realizes it was the wrong thing to say.