How did Junpei know Snake and Clover were abducted together?

I'm playing Nine Persons, Nine Hours, Nine Doors for the first time, and I'm confused.

After Junpei establishes that everyone had been abducted in the same manner, he suddenly tells Snake something like "You and Clover were abducted from the same room, and woke up in the same room", and asks him why that is. Turns out he and Clover are siblings.

But how did Junpei know they were abducted from the same place? Neither Snake nor Clover mentioned that, yet neither of them seem to think it's odd that Junpei knows about it. Have I missed something, or is this explained later?

Solution 1:

I asked this same question on the game's Steam discussion forum, and it turns out this is only explained in Novel Mode, whereas I was playing in Adventure Mode.

In Novel Mode, after it turns out everyone has seen Zero, the narrator says:

As stories were sorted out, the truth became clear...

So presumably, it was during that "sorting out" that Snake and Clover mentioned having been abducted from the same place, and that's how Junpei knows.