Why do we unconsciously search for lovers? We do not understand the spiritual root of this phenomenon. A stable relationship many times leads to super saturation with the same energy. We experience this as boredom, monotony or negativity in the couple. In order to achieve the right exchange of energy between us and our partner we need to be open to receive our partners energy and be also able to give our own and this can only happen when we feel inspiration and joy. But when we dont have a creative approach towards our partner there is no freedom, no joy. When instead of listening to our bodies we listen to our mind which is full of stereotypes and complexes the creative and harmonious communication does not succeed. Tension appears in the couple because the creative energy which should normaly move from swadhisthana chakra (sexual center) towards Visudha chakra (creativity & inspiration), doesnt move and is blocked inside swadhisthana looking for a way of manifestation. if this happens at least to one of the partners then lovers appear in the scene and the desire to communicate with other people to feel joy and happiness. This energy must find a way of expression if we cannot proccess it internaly and if we dont know how to lift it in higher chakras.
Another reason that pushes people to change partners can be the movements of planets and other external influences (friends, external presure or big changes in one's life). In all of these cases unconsciously we start searching for something new, a new path in our life and many times after these influences stop (planets return to another aspect, external influences stop) we also return to our previous state and we regret what we have done.
Alexander - Northern Deer