Informed by family language policy (FLP) as the theoretical framework, I illustrate in this paper how language ideologies can be incongruous and language policies can be conflicting through three multilingual families in Singapore representing three major ethnic groups--Chinese, Malay and Indian. By studying their family language audits, observing their language practices, and engaging in conversations about their language ideologies, I look at what these families do and do not do and what they claim to do and not to do. Data were collected over a period of 6 months with more than 700 minutes of recording of actual interactions. Analysis of the data reveals that language ideologies are "power-inflected" and tend to become the source of educational and social tensions which in turn shape family language practices. In Singapore these tensions are illustrated by the bilingual policy recognising mother tongues (MTs) and English as official languages, and its educational policy establishing English as the medium of instruction. The view of English as having instrumental values and MTs as having cultural functions reveals that language choices and practices in family domains are value-laden in everyday interactions and explicitly negotiated and established through FLP.