After taking a look at the other two sisters wouldn't you say the same thing?  Either she has a different daddy or the other sister got greedy and didn't want to share the looks.Reports have been going around, but mother Kris Jenner keeps saying that Robert Kardashian is the daddy (I wonder how long she can keep this lie up.)  According to Robert's ex-wives, he never believed Kris when she said that Khloe was HIS daughter.  It was even found out that Kris and Robert were not even having sex (some people believe this is just fun, but this is also how babies are made) when the odd duckling was conceived. Even Robert's second wife agreed that Khole looks nothing like her sisters,

He just kind of looked at me and said [it] like it was a matter of fact. He said, ‘Well, you know that Khloe’s not really a Kardashian, don’t you?’ And I said…’OK,’ and that was it.”

Its one thing if one person agrees, but when you daughter thinks there is something funky going on, something's not right!

Khloe brought it up all the time. She looked nothing like the rest. She was tall, had a different shape, light hair, curly hair. Didn’t look anything like the other three children.”

I don't think Kris will ever come out and say that Khloe is not Robert's daughter, but according to What Would Tyler Durden Do Kris DID ADMIT to having an affair while she and Robert were married.  If that is not proof I don't know what is.