A:Answer Hi! Both devices work through Bluetooth Technology, therefore it is possible for a cell phone to pair with the other's earpiece if Bluetooth is in search mode on the phone. Please notice this model counts with NFC, which is a technology that enables Bluetooth devices to establish wireless communication with each other by simply touching the devices together. If both headsets are connected to their corresponding cell phone, they will not connect to each other's phone. We hope you will find this information useful. If you have any further questions, please don't hesitate to contact our Customer Care Team at: 1-888-363-0726.