David is an open, honest person who doesn't have the guile to be deceitful/manipulative - could be described as quite naive in some ways.
It's this truthfulness that has shown up Bea's twisted/warped dishonesty.
Well done, David.
On the other hand, I'm not a complete David fan - he'd drive me potty if I was forced to spend long hours in his company with nowhere to escape to. The last BB contestant to have that effect on me was Marco in BB5 with his incessant seal-clapping
!