Castiel just kissed her, his body saying everything he needed to. I love you, I miss you, I need you. He kept pushing against her, inside her as the lightning cracked outside.
The wall broke under the pressure, or possibly the strength behind the way she screamed his name. It was only his wings stretched up that protected them both from being crushed by falling bricks.
Slipping his arms down, he lifted her up slightly before he pushed her against another wall, the entire building moving slightly under the pressure.