forgot to add this: and sam wouldn't want Jack for a lasting relationship if he were unable to have kids, since she has already proven on the show that that 'normal life' means more to her than Jack.
If he were unable to give that stupid normal life to her (even though she could never have it cause after all she's gone through she's not 'normal' anymore) she would've dumped him (as she did on the show) and find some younger guy who could give it to her (as she did on the show).
I liked it, except for the part where Jack had himself sterilized.
Jack loves kids and wouldn't do anything that would make sure he couldn't have more and if he had, then there would be no future in a relationship with another woman, not even Sam.