His line here is really weird. I don't know what to say. I'd probably put all my money in there and possibly lose it. There's a good chance he has queens or something like that, but could also be tens. It's interesting how he check/called the flop and then bet out the turn for a huge amount, when the turn card almost certainly did not help him. Either he figured he was way ahead from the get go, or he picked a very interesting way to bluff.

I don't know, the more I look over this the more it troubles me. I think you might have been right to fold.