Threatening to leave being the only persuasive argument that works on your significant other is a good indicator you're dating someone with borderline personality disorder.
Ordinary people occasionally need to be knocked back into seeing what they will lose if they keep up their present course of action. Life is full of temptations, most people are not very self reflective, and people naturally push boundaries.
In particular, textual flirting with the opposite sex is something that is easy to fall into, starting innocently and delivering a strong dopamine hit with each correspondence. The dopamine-addled S.O. can easily rationalize to themselves that they are just writing, that their privacy is suddenly Very Important, it's not cheating, and surely that's not innuendo! ("When we finally meet for coffee we'll just be friends.")
The well-delivered ultimatum, although blunt, makes the situation clear and leaves no room for rationalization: the emotions associated with the proto-affair are inappropriate to an exclusive relationship.
I've had to make this ultimatum twice. 50% of the time it has resulted in the recipient suddenly becoming self-aware and making an effort to change her behavior. As a result, I'm quite certain the current S.O. is not BPD.
In particular, textual flirting with the opposite sex is something that is easy to fall into, starting innocently and delivering a strong dopamine hit with each correspondence. The dopamine-addled S.O. can easily rationalize to themselves that they are just writing, that their privacy is suddenly Very Important, it's not cheating, and surely that's not innuendo! ("When we finally meet for coffee we'll just be friends.")
The well-delivered ultimatum, although blunt, makes the situation clear and leaves no room for rationalization: the emotions associated with the proto-affair are inappropriate to an exclusive relationship.
I've had to make this ultimatum twice. 50% of the time it has resulted in the recipient suddenly becoming self-aware and making an effort to change her behavior. As a result, I'm quite certain the current S.O. is not BPD.