And then discusses her new boyfriend...

"After her aggressive behavior was tamed, her following years were much more fruitful. She’s law-abiding; has a decent job and a good education; and has many good friendships and admirers. Especially male admirers; she is very, very charming and adept at attracting guys and maintaining their interest. She uses that old dating guide “The Rules” like a Bible. She currently has a boyfriend of about a year and a half who’s crazy about her, and who I have a very strong relationship with (we live in the same area and spend time together regularly). He is a great guy, very kind, funny and intelligent.

But I doubt she loves him. We’ve had some very honest, in-depth discussions about her mental health since her diagnosis, and she’s been open with me that she doesn’t feel love or empathy towards anyone, even family. When she acted very sad and broken up over the death of one of her closest friends at the funeral, she confessed to me privately that it was all a put-on, and that she felt “pretty neutral” about the whole thing. She has also stated she has never once felt guilty about anything she’s ever done, and doesn’t know what guilt feels like. While she enjoys being around her boyfriend and is sexually attracted to him, I highly doubt she feels much of anything towards him love-wise."

Is the father in the wrong for wanting his potential son-in-law to know?

"Her boyfriend (who might propose soon) has no idea about her diagnosis, and she’s been very upfront with me that she has no plans to ever tell him, thinking it’ll scare him away. I’ve made it clear to her that she needs to tell him the truth before they marry; that he has the right to know and consider it; or I will; to which she always responds, “I know you wouldn’t dare.” I actually would - I really like and respect this young man, and would feel awful keeping this “secret” from him, and letting him walk into a marriage without this piece of knowledge.

I’m not trying to sabotage my daughter’s future. Maybe her boyfriend’s love of her personality and other aspects is enough that it won’t end the relationship. It’s his decision to make; but he deserves all the facts. Someday he’s bound to find out she’s a bit “off”; it can’t be kept a secret forever. AITA?"

Users agreed it was a tough situation

[deleted]:

"Wow. That's the hardest AITA I've read in a long time.

You're ethically compromised either way. It's probably best you stay out of it."

"I think it is above Reddit's pay grade"

bigrottentuna:

"This is absolutely the hardest one I have ever read. I think it is above Reddit's pay grade. OP, you should talk with a psychologist about it."

It's certainly a tough call to make

InfiniteDuckling:

"I agree mostly because the only guaranteed thing to happen if OP tells her secret is that she'll stop talking to OP. OP and the daughter have a great relationship right now. She feels free to tell OP her true feelings without judgement or consequence. If suddenly her plans are ruined she'll cut the source of that problem with zero hesitation and likely not feel anything about losing contact with her parent."

Some users likened it to a real life example of the trolley problem

smileedude:

"This is somewhat a real example of the trolly problem. You can let the trolly run into him, or you can interfere and cause the trolly to run into her. Not intefering is the concensus agreement in a 1v1 situation. Especially when you can't know if the trolly is on track for him, but intefering will definitely turn the trolly towards her."

People who had been in similar situations offered their advice

not_really_neutral:

"As a person who has been stalked for 25 years by a woman with a similar diagnosis, you need to tell him! It is best you protect an innocent person from a horrible experience."

What about private health information disclosures?

saywihee:

"OMG Thank you! I mean the whole situation sucks but this is private information. Private health information! He can't just share that to whomever he wants even when he thinks it's important! There's a reason why HIPAA exists! She legally has the right to say who knows and who doesn't and it's not his right to take that from her."

What do you think?

Salah_Akbar:

"Exactly, the daughter should tell him. The fathers only responsibility here is to counsel the daughter, not to go behind her back."