Hi Scrant, I think it is always tough to spend that time with someone. It feels so intensely familiar and 'right.' The feelings will pass and I would encourage you to sit with them, accept them, meditate and know that you will feel better again - perhaps even just in a day or so. Of course nothing is 'right' about being in her company, given all circumstances and you know already that you don't want to be 'third point' on this triangle - and I would agree that is to be avoided at all costs.
People often say that NC is for you, and I agree that it is easier to find peace when your WS isn't 'in your face' on a regular basis. Sitches like mine are somewhat easier, when there is less need to have contact and kids are older or you have no kids. Just remember this too shall pass and above all, don't be driven by emotion to do something. When you feel in the grip of strong emotion, do nothing is always best.
Take care and I hope the week improves for you. Xx
T 13 M 7 Me 48 H 46 SS 15 BD 7.14 PA D final 5.16 (H filed)
We receive & we lose, and must try to achieve gratitude & embrace with whole hearts whatever of life that remains after the losses - Dubus