if he was really sorry and wanted a purely professional relationship from now on, why is he asking you out socially???
he is a *&%*$#& and is only interested in himself and his reputation - sounds like a narcissist.
He should check his DSM-IV book because he sounds like he fits the criteria:
- has a grandiose sense of self-importance
- is preoccupied with fantasies of unlimited success, power, brilliance, beauty, or ideal love
- equires excessive admiration
- strong sense of entitlement
- takes advantage of others to achieve his or her own ends
- lacks empathy
- believes others are envious of him
- arrogant affect.

just my opinion. you should stay away from this manipulative bastard