Staging is super, but the script could have been finished in a more interesting way, for example, either the awakened girlfriend would have thrown the friends out into the street, or even joined them and looking at her friend obliquely would have screwed her boyfriend much cooler than a mulatto!
The Germans are real gurus in the porn industry, so no wonder, that here the German is so professional with her lovers. Anyway, there's a lot to see,