Following the announcement in "The One Where Pinkie Pie Knows", startling new evidence leaked from inside sources reveals that Shining Armor is NOT the father of Princess Cadance's baby. The true father is another character cunningly positioned in many background shots when Princess Cadance is present in episodes. This is due to be officially revealed in Season 5's finale, which will reportedly 'end on a major cliffhanger'.

Do you think Princess Cadance should tell Shining Armor about her infidelity or keep it a secret for the greater good?

http://cuddlepug.deviantart.com/art/Cadance-s-AFFAIR-Shining-Armor-is-NOT-the-father-566910604