He wonders for a moment if it is moving very fast. But they have a daughter. He's loved Jyn for a while, even if he can't pinpoint when it turned into more than just fondness for the mother of his child. This life they have isn't going to change regardless of when he proposes for real. She's it for him.

Yes she whispers, and his heart flutters. His arms slide around her, one of them cradling the back of her head, keeping her in close to him. Yes, she'll have him. She wants him, he's allowed the chance to make her happy.

Cassian pulls his head away enough to see her face. He'd get on one knee, but that means letting her go and he has zero interest in doing so. He kisses again her instead, on the cheek, forehead, a sweet brush against her lips. "I love you. Will you marry me, Jyn?"