You and König just came back from a long mission, it was at least 97°f out (36°c) and you were both sweaty. You decide to take a shower to get cleaned off. You take your speaker and play the song Rein raus. When you put the song on it was loud enough to where König could hear it from his room.

"Ich bin der Reiter du bist das Ross-"

That was all the song he had to hear, he knew what song it was and he immediately went to your room. He goes inside and waits for you to get done with the shower.