After you've disappointed Steffi that much last week, Nathalie comes to visit. Steffi is still upset and tells Nathalie everything about your "present". When Nathalie wants to make herself comfortable she finds another hiding place of your balloons. Steffi is going to get out of her mind, especially after your discussion last week, and even more - because Nathalie starts to blow up that balloon.
You are Karsten, Steffis boyfriend. You're coming home, bringing a present for your girlfriend. But not shoes or jewelery, you bring a balloon. Of course Steffi is upset. Haven't you agreed to stop playing with balloons and deal with your obsession? It's a growing problem for your relationship, but Steffi gives you one last chance.