I do the same thing and it's mostly not on purpose. I spent a chunk of my childhood in Alabama and another chunk in suburban Philadelphia and have lived in New York for 25+ years. I normally speak with a pretty standard mid-Atlantic accent with regionalisms from all three of those locations making cameo appearances. And then came the year when my husband and I decided to take a road trip vacation through the south and, when a pretty distinct Heart of Dixie accent starting naturally emerging from me as I talked to locals in the various places we stopped, my husband, who'd never heard such a thing from me before, starting looking at me like I had two heads. I didn't even register it myself. it just...happens.
