Oh. Oh!. A whole series of emotions flitted across the boy's face. Excitement, a childish joy, and a moment of seriousness. Because this was a serious moment. He had seen that his sister and his hero were smiling together, at each other, but he hadn't known that they were actually loving each other.
"You love her? You really love her? Not just that stupid infatuation love, like what Pontmercy has?" He was actually a little proud of himself for using a long word like infatuation. Enjolras and the others had taught him well.
"If you ever ever ever hurt her, I will kick you. In the shins." Gavroche looked directly at Enjolras, holding his gaze and letting him see just how serious he was on that point. Because shin kicks could hurt! Especially when delivered by a determined pup like himself. Still, after a moment, his face brightened into a smile. "We'd be brothers? For real?! Like a proper family and everything?"