3-Way Bluetooth Communication?
Should be possible, but only if you setup the Bluetooth module of Arduino 2 as the master. You see, Bluetooth requires to connect to a master. A master can connect to 8 slaves in total. Because Arduino 2 connects to multiple devices (Arduino 1 and your Android device) it should be the master. This also means your Android device cannot connect to any other devices.

Hope this gives you a place to start exploring.