What is a merely transactional relationship? A relationship that involves nothing more than a transaction of some sort. Examples: store clerk and person buying something, beggar and giver, etc.
What is the thing most transactional relationships have in common? The people are usually strangers, and so the scene always involves a process of getting to know each other from scratch. This can be a problem. Sure, sometimes that's interesting. But, usually strangers have WAY less interesting interactions than people who know each other.
To dis MAD TV a little bit, lots of their bits involve this transactional scenario: 2 strangers, 1 is crazy, 1 is normal. Seriously, just watch a few sketches and you'll see this pattern develop... quickly.
There are a lot of interesting directions existing relationships can go. For one, it makes more sense for these people to be in a scene together in the first place. Secondly, the scene flows more naturally, rather than every justification being about why the normal person should go along with the crazy stranger's idea.
Every scene starts with some assumptions. Here's 3 good ones. Assume:
- The characters already know each other
- The characters choose to do something together (even if they don't enjoy it)
- The characters have some history, and will have some future (even if it's not happy)