The openness of underwater wireless sensor networks (UWSNs) exposes them to potential eavesdropping attacks, enabling attackers to trace back and identify the source nodes of packet flows. This poses a significant threat to the confidentiality of sensitive applications, known as the Source Location Privacy (SLP) problem. Conventional packet encryption methods are ineffective in defending against SLP attacks since attackers do not need to know the content of the packets. A commonly used method to address the SLP problem is to establish fake transmission paths, making attackers follow fake paths and thus extending the time required to trace back to the source node. Existing SLP solutions that use fake transmission paths only consider individual source nodes, where the fake paths constructed for different source nodes are independent and cannot cooperate to resist attacks. In this paper, a Fake Path Co-Construction source location privacy protection protocol (FPCC) suitable for UWSNs is proposed. FPCC combines the existing transmission paths and creates co-constructed fake paths to simultaneously protect two source nodes. Simulation results confirm that FPCC, when compared with existing well-performed SLP protection protocols, extends safety time without increasing the number of nodes involved in transmitting fake packets.