<human>: Provide a brief overview of the text.

My SO and their ex are still friends, and the relationship is extremely toxic to say the least, and is also pretty complicated.

I honestly and fully believe and have reasons and examples that point to the relationship being abusive, from the side of the ex, and the manipulation, control and emotional abuse are evident, but my SO stills cares about this person...and I am pretty sure it is because of the abuse and control aspect. I do not know how to bring this up or say that things need to change because of how complex the situation seems. 

My SO means a great deal to me and is very, very, loved and cherished, and it hurts me so deeply to have to see this happening, and to know that their relationship was likely much worse when they were together. 

The ex uses their health, finances, stressors in life and such to seem like nothing more than a victim, and has even threatened to harm or kill themselves when things are rough. To see such blatant emotional abuse and to have my SO be so hurt by this person and to not see it, or not address it, is killing me.

Please, please, I respect that many people would say to leave, but I really looking for any advice for anything I can try, because I want that to be a last resort, as I care very much for this person.
<bot>: My SO has an abusive ex who is fucking with our relationship and with my SO and I want to put an end to it.