I care to love her because I love her... she'd be my sister if she'd been born of the same parents. She doesn't get to 'consent' to my lifestyle choices any more than she would if I were moving across the country. We don't agree on everything, but she's my family nonetheless. I don't think that we won't be friends because of it. I'm afraid of her anger, I'm afraid of hurting her, I'm afraid she will misunderstand.
I have had philosophical discussions with her... we have mutual friends who are openly Poly, and she continues to speak negatively of their choices, and that is where I get this feeling that she'll not understand. Anyway, I'm going to visit her this weekend, and I'm going to try to tell her. I've been over it a bunch of times in my head, and I can't decide how to start the conversation.
"M and I decided to open our relationship a while back, and I've been seeing T since Halloween."
"M asked me to consider an open relationship, and I agreed to consider it to be 'fair', even though I was sure I'd just say 'no', but the consideration changed me..."
"I've been seeing T for a couple of months now... M knows and has been supportive."