I've been advised by a counselor who has treated BPDs for 30 years to have no direct contact... .Her father actually said " She doesn't mean what she says,you know women never say what they mean, she's too much of a coward to kill herself."
Ending a relationship with a person exhibiting BPD behaviors (pwBPD) needs to be final. Otherwise there is high likelihood it will continue in a push-pull, up-down, roller coaster chaos endlessly.
Generally there's no good way to end it nicely, the pwBPD typically characterizes ended relationship as abusive ones. It's because they are in Denial and can't admit they had fault in the relationship. That's why getting Closure from his ex is likely to be a fruitless attempt. Same with continuing a low-key friendship into the future. Theirs is an All Or Nothing world, the gray in between isn't there.
As for the suicide attempts or declarations, it's possible the father is right to an extent. Perhaps she is that distressed. Or perhaps it may also be her way of keeping your son locked into the chaos of her controller & manipulator life. Your son knows he can't go back nor can he help her, that's why he separated. It's so sad, but if he goes back he may lose himself. There's an illustration written long ago. The Damsel in Distress is drowning and screaming for help in a whirlpool. Man jumps in, risking his life, pulls her to safety, then she jumps right back into the water and starts calling for help again. Should he save her again? How many times?
Has he read
The Bridge? Follow the link. You can't save someone if the person doesn't want to be saved. At some point you have to Let Go and Move On.
