One of the most common problems in Ballroom Dancing is maintaining the partnership relationship. When patterns, elements, movements, etc. don't work quite right, it is usually the setup for those actions not the actual execution of the element. The concept of the two-headed four-legged animal must be maintained. All four-legged movement and four-legged feeling is based on this concept.
The leader has the responsibility of defining the relationship of the partners in the physical space of the partnership. He uses the dance frame to establish this partnership relationship. The leader moves his partner's space, not her physically. He maintains his own personal space but does not hold his partner in her physical space. The lady has the prerogative to move around within her own space at will. She is constantly adjusting, counter balancing, powering, etc., all from within her own defined space.
There is a lot of illusion in Ballroom Dancing and the partnership relationship is one of these illusions. One of the illusions is that the partners pass each other and change places. The reality is that the partners only travel with each other or revolve around each other. The partnership space relationship doesn't change. Of course, as with anything there are always exceptions. This description is describing general normal situations.
An example in Foxtrot and Waltz would be a Back Hover element, (aka: Hover Three or Open Impetus). The illusion is that one partner is passing the other. The fact is they are traveling together for one step in "Outside Partner" dance position then revolving around each other on the next step in "Outside Partner" to "Promenade" dance position then traveling in "Promenade" dance position for one more step. The partnership space is maintained for the whole Back Hover element.
Another example would be a Cross Body Lead element in Rumba. The illusion is the same. One step in "Closed" dance position, one step in a modified "Promenade" dance position and one step revolving to "Closed" dance position. Again the partnership space is maintained. Even in "Open" dance position elements like Continuous Hovers in Waltz or Side-By Side Breaks in Rumba, the frame and space is still maintained (it is just a little more extreme).
The head position of each dancer is a key element in maintaining the partnership space relationship. Where the head goes, the body follows. Where the eyes look the head follows. I was involved in some high speed motorcycle riding at one time and you learn very quickly that the motorcycle goes where you are looking. If you don't become aware of this early in your riding, you will end up in the ditch or worse. In Ballroom Dancing, you don't have the same extreme consequences that you have when riding. This is why it takes longer to become aware that this may be a problem in your dancing.
The "Left Side Lead" in Smooth and Standard dancing can cause partnership problems. The partnership offset coupled with the left side lead creates an interesting two-headed four-legged animal. The direction "Forward" is now diagonally forward in relation to the dancer's shoulders. The head position is now not straight ahead of the shoulders, but diagonal as well. Generally speaking, the dancer's cheeks are parallel to each other in all dance positions except "Promenade". Hence the term "Dancing cheek to cheek". The partner's space is the same except the whole partnership moves in a diagonal direction. The direction of the head in relation to the body is now different. The partners must now change what they SEE with this new head position (especially the men) to maintain a consistent and correct space alignment. If the dancer's vision is not changed, the body will revert back to its old flat shape.
It is very important to maintain the relationship between the partners in all dance positions. This is accomplished by a consistent frame position, the proper "Left Side Lead", correct head position, and the understanding that the partners travel with each other or revolve around each other and the leader always moves his partner's space, not her.