I have different pet names for each. For my husband it is Bear or Bunny. He has different ones for me.
For my BF, I have different ones for him (he likes to be called Baby) and he calls me entirely different ones then my husband. I think the first time I called him that is when he fell in love with me.
Neither knows what the other's are. They don't chose to have any contact with each other, except for emergencies. Yes, I have called my husband, Baby since this all started with A. in July.