I’m beginning to think my personal improv mantra is, “make it interpersonal.”
I think there is a huge difference between your roles in a scene and the relationship that you have with the person that happens to be on stage with you.
Roles are established parameters of the two characters on stage (i.e. Lawyer and client, mother and daughter, father and son, teacher and student, and etc.). By definition, it is the proper or customary function. The position one holds to another.
The relationship is personal. It is the connection to the other person that necessitates an emotional response to a situation. To me that is the piece that when absent from the scene keeps it from moving forward. It typically shows itself as two people talking about the activity and not the way they actually feel about each other. (I.e. Lawyer and client speaking about the case, teacher and student speaking about schoolwork.)
However, I have to say some roles have interpersonal components that are built into them and, when combined, two roles at the same time can equal a relationship (i.e. Lawyer and client who are also brother and sister.)
Monkiyo's Musings 
As we’ve been rehearsing, I think it’s been easy to just hit “roles”, but the scenes with deeper relationships are more rewarding. What are some good ways that you’ve tried to work on bringing out relationships vs. roles?
Thanks for commenting and I’ll let you know what’s worked for me. So far (and this is still a work in progress) I have had success with taking three line scenes of who, what, and where to the next level, that level being, playing 1 minutes scenes (30 sec, 15 sec, and 5 sec. scene drills) where they have to establish, what they’re doing, where they are, what are their roles, and what is their relationship. By taking the “who” piece as two separate parts it seemed to help them realize that roles and relationships are two separate things. Also it helps build a common language for the group. When we’re talking about roles, we’re talking about A, when we’re talking about relationships, we’re talking about B.
I’ll continue in a different thread about some other scene exercises that might work for you and developing relationships.
By the way, I did want to mention platform, tilt, resolution, tag. It is the way that I’ve been developing and working the relationship in a scene with a group I’m working with.
I know many long-form people think of it as an overall story arc, but it also works in individual scenes and helps move along the relationship. It’s a Jeff Wirth style of scene work I learned from R. Kevin Doyle.
Here is an improv link to R.’s write-up of the structure.
Also, I have an on-going rehearsal blog where this is the main style focus.
This is how I learned how to play the relationship of the scene and it has been the best way for me to naturally play scenes centered on relationships.