Both sons, Peter (18) and Tim (22)

So he decided to test with his two sons.

Peter was 18 and was in the last class of school. He's the shyest of the two and hasn't had a girlfriend yet.

Tim was 22 years old and the oldest son in the family. He studies "something with economics" and is hardly at home. He was often at university or with his girlfriend Lisa.

On this rainy Saturday afternoon they both heard their father's voice scream "Hey guys, I have to show you something fantastic!".

On the upper floor, the two boys' room doors opened. Tim came out first, "Hey Peter, do you know what Dad wants again?"
Peter stepped shyly out of his room, he was only dressed in a T-shirt and his boxer shorts.
"No, but he just caught me at a bad moment!".
"Oh, understand! Yes, I was on a call with Lisa too! Then you can take care of your latte while I keep my girlfriend busy. Then we'll go down together in 5 minutes!"
"Is okay!" commented Peter, who had quickly grabbed a pair of pants and disappeared into the bathroom, while his brother continued to talk to his girlfriend on the phone.

5 minutes later, the two ran down the stairs to their father.
"There you are at last!" they heard his voice.