The number of portable devices capable of maintaining wireless communications has increased considerably in the last decade. Such mobile nodes may form a spontaneous self-configured network connected by wireless links to constitute a Mobile Ad Hoc Network (MANET). As the number of mobile end users grows the demand of multimedia services, such as video-streaming, in such networks is envisioned to increase as well. One of the most appropriate video coding technique for MANETs is layered MPEG-2 VBR, which used with a proper multipath routing scheme improves the distribution of video streams. In this article we introduce a proposal called g-MMDSR (game theoretic-Multipath Multimedia Dynamic Source Routing), a cross-layer multipath routing protocol which includes a game theoretic approach to achieve a dynamic selection of the forwarding paths. The proposal seeks to improve the own benefits of the users whilst using the common scarce resources efficiently. It takes into account the importance of the video frames in the decoding process, which outperforms the quality of the received video. Our scheme has proved to enhance the performance of the framework and the experience of the end users. Simulations have been carried out to show the benefits of our proposal under different situations where high interfering traffic and mobility of the nodes are present.