This is one of my favorite Giles and Buffy moments.
It’s easy to forget that it was almost just the two of them. Xander and Willow are her best friends but they can never really understand what Buffy goes through. It’s her burden; she is the slayer. But The Watcher comes close to going through it with her. Giles is the one who knows her best and loves her the most and this moment really reminds me of that.