It was certainly not the wake-up that people on their way to work might have expected at 6.30am.
One passenger on the train filmed the couple on the platform with his phone as he boarded a train at Schönleinstraße station in the Kreuzberg area of the city.
Although the pair noticed that they were being recorded, they didn't allow themselves to be distracted beyond raising a middle finger to the camera as the train doors closed.
Police said that charges could only be brought in such a case if someone felt disturbed by the couple's display and reported it to the authorities.
But the couple certainly reached a broader audience than they planned, as the nine-second video has been viewed almost 200,000 times on the LiveLeak website.