The only things that Ennis Del Mar said to Jack Twist before Alma opened the door the 2nd time in 1967 in the book were "son of a bitch" and "little darlin." And, in the book, Jack ran up the stairs, two at a time, to the landing where Ennis was standing. Both of them said, "son of a bitch;" but, I don't think that they were calling each other that, they were just excited to see each other and were at a loss for words. IMO, "son of a bitch" could be interpreted as "Boy howdy! I never thought I would see you again and I sure am too excited to think of something else to say!"
While a modern Ennis might have used the "F-ing" word in talking to a friend he had not seen in several years, back in 1967, the country guys that I was around would have only used the "F-ing" word as the middle or first name of someone they hated with a passion.
