It was me over
there.
In addition to what LR said this could help some:
http://www.cat-and-dragon.com/stef/poly/Labriola/open.html
There is no one way to "do" poly relationships. People organize themselves how they want to when they come to be together.
I think certain relationships have certain expectations.
If we see a woman with a child in a school office and the kid calls her "Mommy" that comes with a whole host of expectations in their relationship that are not present if the child calls her "Ms Smith" like a teacher. We may expect both to be concerned about the kid while under their watch. We do NOT expect Ms Smith to wash children's clothing and pack lunches like we might expect Mommy to. That's an easy relationship example because people have a good idea of the scope of "mother" and the scope of "teacher."
Depending on what open model we are talking about? The scope of expectations attached to words like "boyfriend" or "girlfriend" in a a non-primary free agent kind of model could be different from expectations in a family oriented polyfi model. Or any of the other possible models name or not.
Trouble is we don't have other words. Most cases get words like "boyfriend" and "girlfriend."
If the parties involved don't take the time to calibrate what model they want to practice together and what THEY expect from a boyfriend or girlfriend they could come to trip on that as the relationship unfolds and they discover they mean/expect different things because they assumed they were on the same page rather than actually checking in on that.
They may come to find they were using the same words -- BF, GF. But NOT the same meanings, expectations, scope attached to the words.
Galagirl