What makes a guy want a particular woman's body but tells her he doesn't know what he wants in life? He doesn't want a relationship because he needs to get his personal life straight first===why does a guy say that for?

A trying to be nice I just want to be friends breakup?

Meaning he doesn't want a relationship at present!
I think he being rather straight forward.

Because he's honest enough to admit upfront that he doesn't want a relationship at this time. That's a lot better than leading someone on. Of course, I wouldn't go giving him my body under those conditions. As the old saying goes, he won't buy the cow if he can get the milk for free.

To test the waters on how open you are to having sex for sex sake with no strings attached.

I agree with val. I think he wants you as a play mate but nothing else. He doesn't want the commitment but he wants your 'company' when it suits him!

Omg. Haha I totally agree with the above. He wants a F@$%buddy. Omg don't have sex with him.
Or he doesn't really like you at all and thinks if he says your hot you'll do him
Or he is in a relationship and is looking or a little somthin somthin on the side.

I totally agree... you guys are so funny!

I got deleted for my answer so let me clean it up, He's hoping you'll be a willing playmate when he needs you. He wants your body not your mind.

As everyone has said so far he wants to be friends with benefits, this never works out, it will destroy the friendship.