Why did Sayid feel weird talking to Locke in front of Desmond. He seemed afraid to talk in front of him.

In Sayidd's mind, Desmond might be one of the Others. After all, he was working away inside Station 3, and, like Henry/Ben, all they have to go on is Desmond's word about who he is (remember, we've seen Desmond's flashbacks but the folks on the island have not).

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charlie98210
"Whoa!" she said. "Cry 'Havoc!' And let loose the dogs of war!"
And, like Banquo's ghost, they just won't go away.

crazy naked man predicting lightning strikes - that might give me pause.(lol)

He's has a few reasons to hold back trust. The first person he met up with other than Losties (Danelle) strapped him to a bed and sent electric curent through him. Ben lied to him and the tailies A.L. shot his woman and tied him to a tree. I would be a bit wary of people I didn't know really well too. Besides Desmond is a bit freaky right now.

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Hope is a very dangerous thing to lose. - Sayid

I do what my Rice Krispies tell me to. - Anonymous