Tony was smiling a bit, he was also happy with his daughter for helping somebody. He knew that she was kind and always willing to help. He hoped that Loki wasn't lying though, He had no clue.
But he seemed to think Loki was acting differently. He knew that Loki must be quite miserable and wanting his brother.

Loki was very pale looking from earlier, he kept leaning agaisnt his brother. He didn't feel himself. He wanted to not let go of his brother "Its alright, she can come join."
He smiled weakly. Loki was quite broken right now. He felt like not much would help him. But Riza had been very kind to him. He was looking a little feverish and he closed his eyes. 
He was crying way more.