Who is Sam Morgan’s Father?

We all have been wondering for YEARS who Alexis slept with that helped create the beautiful Samantha McCall Morgan. Recently this has become more of an open topic with actress Nancy Lee Grahn. She has playfully tweeted, naming a few possibilities, most recently John Stamos’ character Blackie Parrish. She also mentioned in an interview that she would like the Father to be  a character that is not currently on the canvas. I have a feeling this story will start to develop relatively soon.