Well, you said you feared you might develop feelings for your wife's gf and thought that she might end up finding you attractive in turn... did I misinterpret that? I didn't think you were trying to say that a triad is ideal or that you were seeking one, by any means. But I also dont think it's something to be avoided like the plague. Everything takes its own shape, is what I'm saying, and either banking on... *or forbidding*... any particular configuration in advance can lead to trouble.
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.