When we had our discussion group this month, there was some pretty intense conversation surrounding hierarchical versus the more organic view of poly. Some people tend to see the whole "primary/secondary/tertiary" model as demeaning, or a strictly ordinal system. Others find it a practical tool that lends clarity to what roles are involved in a specific connection.
On the other hand, the more organic model, where each relationship goes to whatever level possible, without regard to pre-existing structure, can be seen by those who have put years of time and energy into a relationship as dismissive or threatening, to say the least.
As we listened to someone who has felt very hurt by having their place "usurped" with the advent of a new relationship, it pointed out how there are no absolutes within any structure. The landscape DOES shift, and no amount of labeling will change that fact. That said, I'm also a big fan of making conscious choices to nurture and support the people that have been an important part of your life, regardless of how yummy and delicious the newest addition to life is.
It is possible to decide how deep or involved a connection with someone will go. While abundance is a theme that I am a big fan of, there does come a point where some thing's got to give. If you are already close to your maximum capacity, and you add another significant piece to your plate, that time and energy will come out of some one's pocket, and unless you intend to do without sleep in perpetuity, it's likely to be someone that is already involved with you that takes the hit, your job, your friends, hobbies, or your children.
This goes back to the recent post of ideal versus practical. In an ideal world, everyone would flow effortlessly around all of the people that they could possibly feel love for without anyone feeling left behind, excluded, or devalued by the experience. We don't live in an ideal world, but it is a nice idea!
One can choose to accept that there is a level of responsibility on each of our parts to help facilitate those shifts when we add another person to our lives, to help smooth the process for those who we know already love and appreciate us. Alternately, one can look at each person as being totally responsible for their own feelings as the landscape shifts around them. To see each person as a totally independent entity that we choose to interact with on whatever level feels good at the time. Each of these ideas has adherents. Each has drawbacks and upsides. One is definitively more work than the other.
For me, the people who are a part of my life are not like disposable razors, to be tossed when they become dull, or technology, which changes at a steady clip, but more in the realm of favorite things that gain patina, nuance and richness over time. There might be something more flashy on the horizon, but there is always space to appreciate what has gone before, to notice the comfort and relaxation of sinking into a favorite chair, to take your pillow with you on vacation, to love what has come before.