There are five stages of relational escalation. The first stage is pre-interaction awareness. This is when two people don't have any direct interaction. They only observe each other or maybe ask other people about one another. The second stage is the acquaintance awareness. This is when two people get to know each other by asking general questions to skim the surface first. The third stage is exploration awareness. This is when they get personal already. There may be little physical contact, but only minimal. The fourth stage is intensification stage. This is when they spend more and more time with each other to the point of becoming more dependent on one another. Lastly, the fifth sate is intimacy awareness, This is when two people work in sync in terms of mental thoughts, bodily gestures and other intimate connections.
Thus, Bill and Marilyn are in the intimacy awareness stage.
