No, the X-10v3 has only set of input jacks. The other set of jacks is a bypass, allowing you to send a signal on to another component without going through the X-10's circuitry.
It's not a good idea to use a "Y" connector, either, as this will almost certainly cause electrical interaction problems. Your only good option is to put the X-10 somewhere that you can easily reach the back, and then disconnect one player and connect the other.
It's not a good idea to use a "Y" connector, either, as this will almost certainly cause electrical interaction problems. Your only good option is to put the X-10 somewhere that you can easily reach the back, and then disconnect one player and connect the other.