Sounds like when you installed BitcoinABC you installed it into the same location as Bitcoin Core (aka BitcoinQT)... I believe that BitcoinABC does this by default, which is pretty dangerous
![Undecided](https://bitcointalk.org/Smileys/default/undecided.gif)
Not sure if it still does, but it tried to when I installed it prior to the fork... so I changed all the install and datadir's to X:\Blah\BitcoinABC during installation to avoid any conflicts like this.
As ABC is basically a direct port of Core/QT it uses the same wallet.dat format... and if it has installed using the same directory as Core/QT it'll probably be using your BTC wallet.dat
![Shocked](https://bitcointalk.org/Smileys/default/shocked.gif)
I suspect when you used the private key of Exodus in your ABC, because it is "sharing" the wallet.dat with Core/QT, you've also effectively shared the Exodus key with Core/QT.