Sensing circuitry of a first electronic device can be configured to sense a signal transmitted by the second, external electronic device contacting and coupling through the body of the user. The first electronic device can be configured to detect the contact while receiving data from the second device, and determine whether the signal transmitted by the external device corresponds an “intentional touch,” or corresponds to a signal coupling between a different body part and the external device or through a different signal pathway (e.g., electromagnetically, through the air, etc.).