The relationship you develop with the employer is determined by what the union wants to achieve in the workplace. Generally, we desire a workplace where our members are treated fairly, are allowed to be productive and are respected. At the same time, it is a setting in which it is clear to the employer that the union will deal swiftly and strongly with anything that disrupts a positive setting.
In some cases, your supervisor will also be a YEU member, so a cooperative relationship should be your goal.
Remember that you are an equal footing with your boss when acting as a union representative and you can demand to be treated as such. Be cordial but make it clear you have business to discuss.
Here are 12 steps to Establishing Yourself with Management