The Other Woman

Daniel returns home on a college break to help his mom clean up the house after the death of his father. When he arrives he finds a mysterious woman in their house. Daniel's mom tells him that his father was not the loyal husband and father Daniel believed him to be, and the woman in the house is one of many other women his father has slept with, Daniel is in disbelief as he doesn't believe any of the lies.
Is it all true or is there something else going on?