I think you should keep the first version, which is great, and end with:
TODD
You sicken me.
DAVE
Well I just thought it needed to be said.
PAUSE
TODD
It's because she's your sister isn't it?
DAVE
That's got nothing to do with it.
END.
Todd's Girlfriend Page 2
Yes, I still don't seem to have cracked the ending, and now I have two versions of the same of the same sketch, and I am not sure which I prefer. The original is possibly funnier, but goes off at a slight tangent, whereas the second version sticks more faithfully to the original premise. Oh well, something for me to think about.
I like the second one better, I only think the very end might need something else.
Is there anything the witch could do to round it off maybe?