I am too obsessed with current world events to focus, but here, have just two cliches:
"You want the truth?" Mikkel signed. "You can't handle the truth, Emil. Trust me on this."
“I can! You know I can! I am a grown man who has looked giants in the eye and lived. I am not afraid of anything my father might say or do! I am just… curious… as to why the two of you are corresponding.”
“All right, then. If you insist.” Mikkel took a deep breath. “I met your mother while working in Sweden, as an underage apprentice tree surgeon. Our company did quite a lot of pruning on your parents’ estate, and she was always so welcoming, offering us lemonade, and, well… It would appear that the rest of your family recently found out.”
“Found out what?”
"Look." Mikkel handed Emil the letter. "I am your father."
(Cliches come from 'A Few Good Men' and 'The Empire Strikes Back'. I wanted to work in 'Casablanca's Here's looking at you, kid, too, but I ran out of inspiration.)