Assuming the obvious and immediate hugs and I love yous and I missed yous are out of the way:

Shaun would spend the day going on and on about what all he's been up to, and letting his dad know that he's okay, and just spending time together. He would introduce his dad to his team, and show him his hat and his badge and tell him he's going to be the very best trainer ever, and he's going to make him proud. And then he would make his dad stay with him until he fell asleep, when it was finally bedtime. Tell me a story, read me a book, do this, do that, don't leave the room.

And then he would be sad and dejected the next day when his dad was gone again.