he said her name not mine?

As my bf and i were leaving a resturant he says "hey Deidra wait up" (totally not my name)as he was getting the check paid. I say "what did you just call me?" and he didn't even realize he had done it. He said he just wanted to get me to hold up really fast so he didn't have time to think the phrase through. He went out with Deidra before me and even has a son with her. She has been this pain in my side because she will always be in his life.

Question is does it mean something that he called me his ex-gf's name..and subconciously at that? He went with her for 4 years and we've been together only 8 months. I'm sad and upset.