He's "over it." Married, kids, career, laughter, love. He smiles when he thinks of Fred. Celebrates his birthday like any singleton would, maybe with a little more wistfulness.
He's not over it. Angelina and he agreed to marry to seem normal, because what else can a broken person do? They both are less than half now, and they need something to fill it. Both are unsatisfied, but they're polite to each other in front of others, silent in the company of themselves. It doesn't matter.
Every time he sees Fred his heart breaks even more, though it seems impossible. He can never call him Freddie, never tell him a joke. His children think he is a quiet, reserved man, because with them, he is. Roxanne still makes him feel hollow, because she looks more like Fred then the boy who was named after him.
He loves the idea of his joke shop, but not the physical form. It's still called Weasleys' Wizard Wheezes; the day that apostrophe moves is the day he dies. Always, he feels so alone. Even though Ron stops by almost every day, and they joke around, it's nowhere near the same. Ron's humor is too dry, there's no sparkle of wit in it, and sarcasm quickly turns to insults and complaining. Why can't he be funny for the sake of being funny?
He can't move on. He'll never move on. Everyone else has, so he lets them think he's with them. It's the least he can do.
All he has to do now is wait to die. To become whole again.