Given you're suspicious about these people and the way you talk about them, they are most likely well aware that you're on a fishing trip feigning interest.
People like you are always more transparent than you realise.
Apologies if it wasn't clear, I am a different person to the one you replied to, and am not suspicious - I was commenting on the other person's suspicion and indeed said that it wasn't normal.
I'd say you're missing the hint that it is none of your business.