Is jack nicholson christian slater's dad?

Answer 1

 'The postman always rings twice was released in 1981 and Christian was born in 1969. Not very likely, eh?

(To the bottom answer)

Answer 2

No Michael Hawkins is   It's evident by looking.  He played Frank Ryan for a short time on Ryan's hope.

Answer 3

I don't know, but it would seem so.
In the early 90s I remember (even though I was young) that they had a DNA test or something, because Nicholson had dated Mr Slater's mother.  She never knew who Christian's father was, from what I understand.  She was a casting agent then, a well-known one.  
That's all I know.

Answer 4

The rumor is that Jack Nicholson actually mounted and impregnated Jessica Lange during the filiming of the Postman Always Rings Twice and Chirstiasn Slater is the product of that mating.