What rehearsal techniques would you use to explore the relationship between [Character 1] and [Character 2] in the above extract?

Firstly, I would want to address the three main aspects of drama/theatre that could be used to communicate a relationship: spatial relations and proxemics, non-verbal communication and verbal communication. This answer can be used for any question like this regardless of what characters you are asked to talk about. What is important is that you manage to identify if they have a positive or negative relationship so that you can adapt your understanding of dramatic elements to show this correct sort of relationship.So, for example, if you have a situation in which Character 1 is aggressive and threatening towards Character 2, then you could explore this through changing the space between them to communicate this. Make rules in rehearsal when running through the scene that demand that Character 1 always tries to close the space between him and Character 2 and tries at all times to get close to them while Character 2 always tries to move away from Character 1 attempting to make distance between them. This will give the audience the impression that Character 1 is making Character 2 uncomfortable and on edge.