OK, I really didnt understand at all, but now I think some glimmers are coming through.
Si was OK to have around a certain amount before. Then when she and Matt were getting it on, it was OK to have her around more (even co habitation). Then, when Matt decided he was mono, suddenly it was not OK to have Si around, even as much as before the attempted romantic/sexual relationship. In fact, he'd rather never see her again. And never have his wife see her again, even better.
Love withers under constraint; its very essence is liberty. It is compatible neither with envy, jealousy or fear. It is there most pure, perfect and unlimited when its votaries live in confidence, equality and unreserve. -- Shelley
There's no lying in polyamory!
I'm a 58 year old woman with 2 partners:
miss pixi, my live-in gf, 36 (together since Jan '09)
Ginger, bf, 61, married, lives nearby (together since Jan '12)