On opensea, I converted (wrapped) 1 ETH to 1 WETH, which is equal to 2 x 0.5 WETH = 1 WETH. I then spent 0.5 WETH on 3 items = 1.5 WETH, which is greater than the amount I had.
how is this even possible, and where is the WETH balance even kept, in my MetaMask wallet (i don't see it there) or in my opensea account?