Who will you believe?

Smidgin This innocent face is of Smidgin. She says that she is perfectly honest and would never lie to you. She is ashamed to admit that her puppy friend, Epsilon-pi, tells lies.

Epsilon-pi This darling little face hides an evil mind. She will tell you that I tell lies. How could she?

Me: I will tell you the truth - BOTH Smidgin and Epsilon-pi tell lies.

Who will you believe - Smidgin, Epsilon-pi or me?

How can you be so sure? Can you explain your logic fully and clearly, giving the logic behind your reasoning for each of the three players.

This is not about guessing - there is a mathematically logical reason for the correct answer and only one is possible.