Are you talking about him getting raped then impregnated without his knowledge? I actually felt bad for him in that one.. what jerks the rest of his crew were.
And Harry Kim is like the Anti Christ of all things sexual.. not only does he screw up(and no pun intended there) his own chances, but his mere presence destroys all sexual energy in the room. Like Janeway's almost kiss with that French alien previously mentioned. Just call him Ensign Cockblock.