We know how each of us views the world through a particular filter, each has characteristic ways of interacting; and responses from the other eight will vary with each.
So an Eight/Nine couple might be drawn together initially because of their mutual comfort with the Eight's providing structure, then both begin to feel some pain from that same dynamic. Style Eight has plenty of ideas but may forget to include Nine, who hasn't initiated any ideas. Nine goes along with Eight, then obsesses over being left out. Over time, Eight's exhausted from having to "hold up the world" (a belief they create and sustain, of course). Nine's equally tired of feeling "invisible" (ditto).
The gift in mutual development is not having either partner on the hot spot because both are learning about themselves within the relationship. This does require courage, however—to take personal responsibility for the relationship, to deepen our own self-awareness, to accept and integrate parts of ourselves we have not wanted to know and see, moving attention away from how we and our partner should be and toward who we are.
Step 1: Each share with the other your understanding of your Enneagram style in general and how, specifically, that plays out for you. What doesn't fit for you about that personality point? What are your gifts? What problems do you think your motivations and behavior do or could create in the relationship? Ask each other for feedback and listen to it.
Step 2: Create a clear picture of what the transformed relationship will look like and commit yourselves to learning as you go. Pick two or three areas of mutual development (don't overwhelm yourselves with too many promises); set some priorities and work on them one at a time.
Step 3: Be alert to how you get in the way of your own progress and stay committed to the transformation—notice and affirm each other for the ways in which you stick to the plan. When one or the other of you gets hooked into an old reaction, instead of placing blame, try to understand how it happened and what either of you could do the next time to keep from getting caught up in the old pattern.Examples:
How these steps might work with styles Nine and One.
How styles Eight and Two could improve their relationship.
A style Four is divorcing a style One.
Four/Five relationship issues.
A couple with styles Four and Six adopt a child.
Mutual development with styles Six and Nine.
Dynamics of Eight/Six patterns in relationship.
Dynamics of Eight/Eight relationship patterns.
A couple interrupts a Nine/Eight interaction pattern.
And a bit about styles Three and Seven at work.
Two Nine friends with different instinctual subtypes.