why did Celebrimbor allow Sauron?

[Inziladun]

Blazes, this does take me back! It feels longer than it really is since I first saw this thread.
I don't think I'm convinced Celebrimbor did suspect 'Annatar'. The UT chapter The History of Galadriel and Celeborn, which seems to have the most detailed information regarding Eregion, gives no indication of any insight of Celebrimbor's which told him Annatar was not what he seemed, until Sauron set the One upon his finger.
Also, it wasn't only Celebrimbor who had dealings with him there. It has been mentioned above that Galadriel suspected Annatar, but it really does beg the question of why, if she knew his true nature, she allowed him to remain and have his will with the rest of the Noldor.

Sauron used all his arts upon Celebrimbor and his fellow smiths, who had formed a society or brotherhood, very powerful in Eregion, the Gwaith-i-Mírdain; ....So great became his hold on the Mírdain that at length he persuaded them to revolt against Galadriel and Celeborn and to seize power in Eregion.

If Celebrimbor in his heart knew Annatar to be evil, why would he have allowed things to go that far? After all, in the same chapter there is mention that Celebrimbor may have loved Galadriel at one point.
Granted, that implication is found nowhere else, but even if he had no romantic feeling for her, I just can't see him rising up against her at the suggestion of a being he was aware was truly bad.