Superman was bored fighting crime everyday. So, one Friday night he decided 
to go out in the town to have some fun.  He drops by Batman's house.  "Hey 
Batman", he says "Wanna' go out tonight?"  "No, I can't," replies Batman, 
"The Batmobile is broken and I gotta' stay home and fix it, or else I won't 
be able to fight crime." "You loser," says Superman, and he flies away.
He decides to stop by Spiderman's house.  "Hey, Spidey, how about hitting 
the town tonight, you and me," he says.  "I'd love to, but I can't," 
replies Spiderman. "My web is broken and I gotta fix it to fight crime." 
 Superman, disgusted, says "You loser.  Stay home on a Friday night and fix 
your damn web."  So he flies away.

While flying from up above he spots Wonderwoman stark naked and lying down 
on her back spread-eagle.  Superman thinks, "Hey, I'm Superman. I can fly 
down there at the speed of light, have a quickie and fly back out and she 
won't even feel it."  Superman flies down, does a quick in-out-in-out and 
flies back out at the speed of light.

Wonderwoman says, "What the hell was that?"

The Invisible man says, "I don't know - but my butt hurts like hell."