I try to understand everyone as much as I can. This has been the group that I've thought about the most. From the start, I wonder how this is discovered? How do you bring it up to your partners(s)?
Some people think they're greedy, some say that they want an excuse to "cheat" (by virtue of most poly relationships, it's a mutual understanding, not cheating.)
I still don't fully understand the relationships. Being emotionally open to another person, I can see happening. The sexual aspect is a bit more confusing.
Still, my heart bleeds for people that different, legitimately. Their relationship preference is so outside of the standard that there's no way that there could be that many so that they can be in their ideal situations. It's an unfortunate situation for all involved and there really isn't one person to blame...