The problem with leahs case is there are a lot of conflicting statements out in MSM. The police say one thing and the family say another. This interview with Leah's dad contradicts the statements made by police and so gives the impression mr X was not looked into as thoroughly as other possibilities. None of us know for certain what is true and what isn't but statistically if a young girl/woman disappears and later it's revealed she had a secret married lover then there is strong possibility that the lover is involved in the disappearance and so people naturally gravitate towards the possibility of foul play in Leahs case (IMO). I'm not saying that's whats happened or that you are wrong but just trying to explain why the theory of Mr X comes up time and time again.
SBM/BBM
I agree with you completely that the disparity between what the family allege and what the police say is a huge problem.
And I agree that
if she was having a secret affair with a married lover, the index of suspicion would be high and you would want the police to investigate that person thoroughly. But I disagree that any evidence of that affair has ever been revealed - indeed it would be very helpful if anyone with any evidence
would reveal it. And yet, more than two years on, nobody has, as far as we know. Leah's family have the ear of both the police and the media, and also regularly communicate directly via social media. If they had any actual evidence, as opposed to hearsay and hypothesis, I'm confident we would have heard about it by now. Notwithstanding, the police have investigated and have ruled that person out.
I also don't really buy the idea that the affair, if it ever existed, puts X in the frame for anything criminal. If the hypothesis is that he murdered her, or had her murdered, because she was pregnant (which I've read on here), then I think there are far lower stakes ways for him to have dealt with that.
It's possible though. Virtually everything in this case is possible, which is why it's so interesting and simultaneously so frustrating.
The reason why there is no evidence of a relationship between X and Leah is pretty simple:
X was getting married later on in 2019 and wanted to keep this relationship as quiet as he possibly could.
Hence no photo's, cards or love letters. It seemed he managed to persuade Leah to keep their relationship a secret, even to the point that she was the one getting taxi's to see him rather than the other way round.
But it's also possible that there's no evidence because it isn't true.
The police said that Leah was having some anxiety issues at work before she disappeared, and I believe this is because X had ended their relationship - probably because of his impending marriage. Maybe Leah had found this out, not only had someone that she may well have fallen in love with dumped her but also he was getting married later that year - this could have been all too much for Leah.
IMO the split was the catalyst for Leah's disappearance on the Friday morning. Voluntary disappearance? suicide? abducted? All these options (and others) are still on the table.
I agree that in photos she often looks anxious.
For me, the turning off of her geolocation on her phone the night before speaks to a planned disappearance, and I think that the weekend a couple of weeks prior, when she lied about where she was, was when she initially planned to disappear but that she got cold feet.
I think lots of other things! But I can't evidence any of my opinions either. So we are all just hypothesising.
JMO