AA - Paired board on river!

Hello!

I was just wondering about a hand how you would have played it and when you should fold AA.

All of your opponents and yourself have 100bb stacks.
Say you get Ad As, and raise 4bb PF. You get 2 callers and the flop comes Kh Qh xd

You bet out pot on the flop, and one of the fellows in the hand folds whilst the other one calls.

The turn card is a blank. You bet out pot once again, and you get called.

Now the river comes Ks! A paired board. You decide to check, and your opponent decides to go all-in, forcing you to either put all your chips into the center, or fold.

What would you do?

I'm having a discussion with a friend of mine about this type of hand. He thinks one should call whilst I would fold. Comments are appreciated!