Unlikely Cover
Second Impression
Type of Feat: General Prerequisite: Bluff 5 Use: Automatic.
If an observer sees through your disguise with a successful Spot check, you can (as an immediate action) attempt a Bluff check at a -5 penalty to convince him that he's mistaken.
Use the observer's Spot check result as the DC for your Bluff check; if you succeed, the observer ignores the evidence of his own senses in favor of what your disguise attempts to show.