Ahaha no, you’re right, we can’t “diagnose” her at all. We can offer possibilities based on what he told us, though, which is all I think he really wants. None of us can say for certain what’s up with her, but some of us have had similar situations with people and can share that information. For some reason the guy’s response just kind of irked me at first haha. Just because we’re strangers on the internet doesn’t mean we have zero understanding of anything medically related. I understand what his point was now, though.

I also wouldn’t necessarily call her problem irrelevant to OP, though. She’s a big part of his life, now. He even plans on marrying her. No one wants to be in a relationship with someone that consistently lies to them, and this is an especially serious problem - maybe the information won’t help him in the end, but advice from strangers can help him realize that he’s not a terrible person for doubting her.