He looks like he could cry at any moment.
Blaine just realized that he loves his best friend, and that means he gets to love his best friend. And just… that is a wonderful feeling. To be able to share that amount of closeness with one person. To be able to love them on so many levels.
I don’t think Blaine has ever felt this way about someone. We don’t know much of his back story, but we do know that he’s never had a boyfriend. He’s felt puppy love before, but this is different. You can tell. This is deep love. This is Blaine falling for Kurt hard.
It is so overwhelming to realize such a huge thing is such a short moment. And I’m so happy for both Blaine and Kurt that it finally happened.