@AshJen87 Thanks for that update! It's terrible that you're having this much trouble with a save that clearly means more to you than others. I almost always base my main character on myself (though he's in much better shape than I am :-) I think you were right about keeping them separated. As you said, they are "reminded" of the "pain" when they are near each other, which likely prolongs the duration of the sentiment. I spent several hours playing a separate game save with my two dads and two new toddlers. I hope this isn't considered spamming because I just wanted to share my own findings. Anyway, I think this will be my last post on the matter because I'm giving up trying to understand how sentiments are assigned but at least I have a better idea of how long they last and how to mitigate that duration. It will be a long post but please bear with me as I think it may help give more savvy folks reading this some needed input.
1. It's obvious sentiments are tied to the positive / negative relationship points earned from interactions between sims but it is not clear if there is a certain number of relationship points required to generate a sentiment. The type of sentiment applied seems random and arbitrary as I was not able to replicate specific sentiments tied to specific interactions. While some interactions generated negative sentiments, the parents and toddlers had numerous interactions that did not generate any sentiments at all. It seemed the positive interactions between adult and toddler far outnumbered the negative ones, yet none of the positive interactions resulted in positive sentiments for the toddlers, only the adults. At any rate, none of the interactions undertaken by the parents in this game play should be considered truly negative, since their intent was focused on the toddlers' well being. Also, players are unable to control sims' reactions to every interaction (especially those from toddlers' random defiant behavior) and therefore should not be penalized by long-lasting negative sentiments that significantly impact the game.
2. It seems the sentiments linger while the sims are in the same household, even when the sim with a negative sentiment is separated from the offending sim. When a toddler with a festering grudge was removed from the household, this "long term" sentiment was gone after three sim days. When a toddler with a hurt sentiment remained in the house, this "short term" sentiment lingered for four days but was gone within the same day of removal from the house. To me, this indicates sentiments will likely linger twice as long if the sim remains in the household or longer if there is no separation at all.
3. While I have not yet experienced negative sentiments between adult, teen or child sims, my guess is that sentiments were not designed to mesh with toddlers' already erratic emotions and defiant behaviors. Since these negative sentiments are gained from negative reaction to non-violent interactions, there must be a way to either remove/disable sentiments or to shorten the duration when related to friendly interactions as well as normal parenting interactions; i.e. bathing, potty training, comforting, teaching, etc. Perhaps the duration could be kept as-is or extended when sentiments are related to "mean" interactions, such as yelling.
Details:
Neither of the dads developed any negative sentiments toward each other or toward either of the toddlers, during this game play, and at no time did either dad do anything "mean". The play was focused solely on the care and feeding of the toddlers; potty training, bathing, comforting, teaching etc. The household consisted of the following characters:
Dad: Jona is cheerful, self assured and a music lover
Dad: Andrew is childish, self assured and a music lover
Toddler: Jeremy is fussy
Toddler: Aaron is independent
Within the second sim day of play, Jeremy developed a "festering grudge" against Andrew related to potty training defiance. I removed him from the household the next sim day. After the third sim day of complete separation from the household, Jeremy no longer held any sentiments. I added him back to the household after the fourth sim day of separation (around six sim days of play time). Towards the end of that sixth sim day, Jeremy developed a "festering grudge" against Jona related to defiance to flash cards: teach basic needs. This is where I gave up and removed both toddlers (see below); random and frustrating.
Within the second sim day of play, Aaron developed a "hurt" sentiment against Jona related to calming down from being angry from defiance to potty training. I did not remove Aaron at this time but kept him separated from Jona. After three sim days of separation, the "hurt" sentiment background had changed to half gray, half red. Then it changed to all grey after four sim days of separation (around six sim days of play time). Since this coincided with Jeremy's second "festering grudge", I removed both of them from the household; roughly 10:30 am sim time. By 9:30 pm sim time the same sim day, Aaron's grey hurt sentiment was gone.
I will continue to monitor this thread for updates, hopeful that someone will be able to figure this out and offer some kind of life line. Thanks to everyone trying to help!