Parents of deaf children must decide whether to raise their child using spoken and/or signed language. Multilingual parents have the additional decision of whether to use multiple spoken languages (with or without a signed language as well). These communication choices -- which can be both explicit and implicit -- can change over time and are known as a Family Language Policy (FLP). This study provides a reflexive thematic analysis of semi-structured interviews with multilingual parents of deaf children who chose spoken language multilingualism (SLM), and with multilingual parents of hearing children who also chose to raise their children with more than one language. We identified four key themes which influenced the decisions parents made on SLM: (1) additional benefits for the child; (2) knowledge and professional advice; (3) family and social influences; and (4) family dynamics and negotiation. The results highlight the complexity of the decisions behind FLPs for multilingual parents of deaf children and the strong influence that factors within and outside the family can have.