Because
It's the first night of many when Henry will be awoken by a text from Natalie that says "plz come get me."
Because he doesn't know this will happen a million times after this, Henry panics. He asks Natalie where she is, and rushes to his car.
Because this is the first time this happens, he speeds to the club, praying he won't get caught.
Because this is so new to him, he looks around frantically until he sees Natalie huddled in a corner, looking like she wants to disappear.
Because none of this has happened before, he runs over to her and hugs her tight to him. "Don't ever scare me like that again," he whispers, almost to the point of tears.
"I won't," Natalie promises.
And because he's so relieved Natalie is okay, he believes her.