I realise that strictly speaking, what I'm talking about above is not polyamory. It would probably be a FWB for S at best. Nonetheless we are in an open relationship now, so a poly situation could easily develop for either one of us at some stage.
Me: A, male, 39.
Her: S, female, 36, my LTR of 14 yrs.
A and S both straight.
Ours: one beautiful 3 yr old child.
Relationship status: recently opened.
Mine: not yet
Hers: B, male, 38, straight. A past love interest of S (unconsummated, with close calls) recently back in S's life.
B married to K, both mono. B has only hints of our open status.
B would probably have an affair with S if she pursued it - she is very sexy and seductive