What is the right course of action here?

In this scenario, the correct actions involve allowing both the motorbike and yourself to proceed ahead of the yellow car. According to German traffic rules, when approaching an intersection with right-of-way signs, vehicles must yield to traffic in the line of sight.

1. The motorbike can go ahead because it is navigating within its lane and may have the right of way depending on the circumstances, such as the placement of the signs.
2. You may also proceed ahead of the yellow car if you have the right of way and it is yielding to you as per the road rules at this intersection.

It is essential to understand that both vehicles must adhere to right-of-way regulations to ensure safety and avoid accidents. Always assess the intersection situation and any accompanying signage.