Kurt smiled into the kiss, loving the fact that it seemed like Blaine couldn't stop himself from doing that in reaction to what he'd said. He knew that feeling, when he couldn't find a way to express what he felt toward Blaine without just searing their mouths together and hoping that somehow his lips and tongue would be able to say it for him.
He sucked his lower lip into his mouth, tongue tracing along it briefly before he pulled back enough to murmur, "I love you."