Bill is only able to resist the tugging long enough to get the envelope back and then he's pulled along by Boo as he tries to explain things to Kate.

"Yeah. No, she's still... It was someone's idea of a lesson, that's all." He shakes his head and can't help a smile. "Although Jennifer Aniston I could totally get if she walked in here."

Kate's reaction is a relief enough that Bill can breath easier and joke. He's still going to burn the envelope and it's contents first chance he gets.