Before. Me and my partner had been together for almost five years, when we formed the thrupple. That happened in June 2018, and the infidelity happened in August 2018. In a way, it was a betrayal of that partner too - although it was so fresh at that point, and we weren't monogamous with him - even though he didnt see anyone else), that I'm not sure it counts.
Definitely the break up of the thrupple - me in August 2019 and my BS in Dec 2019 had an impact and influenced the emotional terrain, but I think that even had we all stayed together the betrayal would still have cut deep for all the other reasons. My BS also started to feel the impact of the betrayal really keenly (nightmares, unable to have sex with me without panic/fear response) before we all broke up, in July 2019, just before the anniversary of DD. By that time, me and my other partner were already on the rocks, but the actual response came before the break up. My BS was really devastated though as their ideal arrangement was with the three of us, and our other partner didnt think it would be possible to maintain when all three of us were (*not work) together.
Re the entitlement, I have thought about that. It is an entitlement on 2 levels too - one, to take for granted that my BS' love would be unconditional, and two, that I would take my own pleasure with the AP despite the rules me and BS had mutually agreed on. One of the hard things about this is coming to terms with the ways in which you were a bad person. No one wants to treat their loved ones terribly, and yet that is what it is to be a WS. It does cut to the core ideals that you have about yourself.
EDIT - I thought I would add after reading that person that quoted the Skyrim quote (lol, but good quote) that I think I have moved away from that paralysing shame state. I feel like it's gone from denial of how bad my actions were, to deep shame, and not wanting to look/think about what I did and the impact it had, to finally looking at things more clearly and head on. I do thank my BS and this forum for that too.
[This message edited by 030303 at 4:41 PM, March 7th (Saturday)]