What is the purpose of telling someone that they are your FP? Maybe I’m just a suspicious jerk who doesn’t understand what having a FP is like, but doesn’t that give them both the tools to put distance between you and also the reason to do so? I’d think the important part is that you know they are and you choose to behave in ways that mitigate the disordered thinking and behavior around that dynamic. 

Fwiw, still not sure if I was diagnosed correctly, I may or may not have ever had this kind of relationship - I might have just been really naïve and way too romantic and trusting. Now I’m a bitter old lady just trying to understand.