Yep to all that's been written. LVFCS, you and I and MonoVCPHG are all secondaries: lovers of someone who is in a poly marriage.
Someone posted a link to the Secondary's Bill of Rights
on another thread.
In a nutshell: I have the right to be treated with dignity, respect, consideration, and courtesy. This is true of any relationship, regardless of its form and regardless of its status. Using the word "right" in this context means "This is something that it is reasonable and normal for me to expect, and reasonable and normal for my partner to give me."
The discussion there has a lot of good ideas.