While use of a racially and/or ethnically marked variety by an outsider is often interpreted as an act of linguistic crossing or linguistic appropriation, this paper adopts a second dialect acquisition perspective to account for instances of use of ethnically-marked dialect features by individual speakers in situations of inter-racial/ethnic contact: white women with significant social, kinship, and residential contact with African Americans in Columbus, Ohio. Linguistic data are obtained from sociolinguistic interviews and interactive speech data from white adult female speakers who participate in similar types of dense African American social networks, but differ from one another with regard to their use of morphosyntactic and phonological features associated with their second dialect, African American English (AAE), and the ages at which they began to have significant contact with native speakers of AAE, which range from early childhood to early adulthood. This paper’s general finding—that age of acquisition (AoA) of AAE matters among adult whites who use AAE-linked features—is supported by numerous previous studies that address SDA across other various other social, regional, and national boundaries (cf. Siegel 2010). However, AoA is found to impact speakers’ current use of morphological and phonological features differently and in a way that is somewhat anomalous with the SDA literature. Across the sample, a statistically significant correlation is shown between speakers’ ages of acquisition and the qualitative range of AAE-linked morphosyntactic such that the lower the speaker’s age of acquisition, the wider the range and the higher the rates of AAE features used, but the same correlation is not found for speaker AoA and use of AAE-linked phonological features. The key to understanding the patterns of use of AAE-linked phonology lies with outliers within the sample who provide additional insight into the life circumstances beyond AoA that impact SDA attainment. By considering both speaker norms and outliers, the benefits and limitations of second dialect acquisition analysis of adult use of racially/ethnically marked features across ethno-racial boundaries is explored.