I know a few polyamorous people, they all have failed relationships later on, even the one that lasted for several years.
Because people do not respect hierarchy, the waters gers muddled and the trust in the relationship is destroyed.
My own open relationships had very clear cut rules, and they worked because of that.
Showing some affection and care to Bob is fine, including him in life decisions or even solo trips with Mila is already a disaster for Paul and the marriage because it spells one of these 2 things:
- Paul is a worthless and spineless cuck that would forego meaningful time with the person he married to fuel his subhuman fetish
- Mila has already moved on and doesn't care about the marriage at all, unless it is to go back and "report" to fuel her own fetish
(In the plan there is a trip to Paris, Mila's dream since she got married and we have Bob going instead of Paul, I don't know if this will be implemented or not)
Bob is not a partner to Paul he is not even a friend, he would be a boyfriend to Mila, that is it.
This is not the premise both Mila and Paul set at the beginning, sure things can change, not for the better tho.
Granted, I see the same issue if we got the reversed situation in the loyal path, but there we see Paul really caring for Mila, and Mila being the initiator for the Kiki stuff.
I doubt any of them will see Kiki as a main partner and more as a "little sis" (I lack a better term).
As usual, let me underline that these are my own projections and ramblings, aDDont and Silken are at work, I'll wait for what they conjure up.