Methods, systems, and media for presenting media content items using multiple devices

Mechanisms for presenting media content items using multiple devices are provided. In some embodiments, methods for presenting media content are provided that include: detecting an offer to initiate a purchase of a content item being presented using the media device, wherein the media device has not been authenticated with a content service that provides the content item; in response to detecting the offer to initiate the purchase of the content item when the media device has not been authenticated with the content service that provides the content item, causing the media device to be discoverable by one or more mobile devices that are connected to a same local area network as the media device; encoding offer data corresponding to the detected offer to initiate the purchase of the content item; in response to receiving a status request from a mobile device that is connected to the same local area network as the media device, transmitting the encoded offer data associated with the purchase of the content item to the mobile device, wherein the encoded offer data causes a payment user interface to be presented on the mobile device; receiving a cast request from the mobile device to cast the content item on the media device; and in response to the cast request, executing a receiver application on the media device that accepts the cast request from the mobile device and causes the content item to be presented using the media device.