If Buffy knew what he was thinking about, her mind would be reeling as well. She'd also be completely shocked at how he came to that conclusion.

"He's grumpy at first. You just have to give him some time." They're good friends. Buffy can't speak for Derek, but he's probably her best friend here in the complex.

She's still not seeing how that's leading to what Alcide is thinking.

"Seriously, we don't mind you joining. It's not a big deal. We just have to be careful not to get caught, you know?"