Childhood Enemies

I need a cheat command or something to remove this Childhood enemies from the relationship. I have searched and searched and I couldn't find anything. I did find this comment on Reddit.....

If this is true then it is not reasonable. If they can grow up and show to be good friends, best friends, close and amazing compatibility......this would tell you that they've gotten over it and moved on. They cannot have one conversation without losing it on each other and they can't build good sentiments because it trashes them every time this happens and i am sick of it. I am not going to make their forget each other or anything that will make them fully lose their history. So skip any suggestions for that kind of nonsense. 

It seems like most things in this game can be added and removed, raise or lowered in some way. There must be a command that would allow this childhood enemies to be removed. This is wrecking my plans to marry the sisters to two brothers. I thought I could deprogram it out of them but now I see I won't be able to do it naturally unless i am missing something. I don't want to split the brothers up or use different sisters. 

Are sims like objects saved into the game? is there a way to edit them? Something like that? 

Please help :)