SENSE OF HUMOR ALERT. PLEASE ladies and gentlemen forgive me for sounding crass with this post...
When I was an undergraduate I remember my room mate telling me about a short story or some kind of analysis of Superman and Louis Lane's love life I think was entitled: "Man of Steel, woman of Kleenex." I think Harlan Ellison may have been involved but I'm not sure.
At any rate, the movie where Christopher Reeves Superman gives up his powers to marry Louis then made more sense to me. Now if his skin at the cellular level was impervious to kenetic energy weapons or peircing and these "super charged cells" also gave him incredible speed and strength that should apply to ALL of his cells including his sperm.
Think about what catastrophic internal damage "the man of steel" could do to a normal woman if he had sex with her and he ejaculated inside her.
Gives new meaning to the phrase "Faster than a speeding bullet."
Just a thought..
KF