You did not snoop. Snooping would be accessing a partner's password protected area with the goal of exploratory learning.

You did not do that.

You encountered what appears to be irrational pathological lying.

You witnessed how the man corrected his own child on his age.

That after that you turned over the ID - but who would NOT?

Either that, or you can say that you accidentally noticed the idea on the coffee table. I doubt that he always puts it face down.

Since this is so irrational, I would not confront him in person. Either you decide that this is too weird and break up sans cause (dating "at will"), or, you send him an email or text and NOT meet with him until he explains this to your satisfaction.

This is because the conduct has been so weird that one basically does not know what to expect so it is better to be on the safe side.

Note that I can see how a guy would reduce his age on an online dating site, and would never fault him for it.

If a 51 year old does not want to be in the bracket [50-59], but wants to be in the bracket [40-49] and states that he is 49, I see no harm in that - the man in this example simply wants a level playing field and a workaround the dating sites' system of age brackets - a system that is unfair.

But, at least on the 3rd date if not earlier, you explain it to your date.

Can you see any other rational explanation for a man to state his age at 2 years younger than real?