[His smile comes back when he realizes Hiccup is perfectly fine with all the science talk. It's pretty sweet, having someone that will listen without complaining and will even understand too. He could really get used to this... hopefully.

He chuckles along, taking a sip of his own soda can before speaking.]

My experiments... they are a little bit dangerous, so my teacher gave me a special permission to use that place you see in the pics. It's underground but huge, I have fully free range in there. A secret lab of my own... [Using the arrow keys, he shows Hiccup some more pictures of his lab, with full shots of the Tesla coils and the cage, finally ending with a shot of the floor.] ...whiiiich means my master took the chance to make it our training grounds too.

[He rolls his eyes, but it's obvious that he is complaining for the sake of it and is fonder of Balthazar that he lets on.]