I thought the new Star Trek: Beyond was the first to show two daddies (Sulu is married and has a daughter with another man), but no---Star WARS was first, in this Campbell soup ad from last year (Oct. 2015):
[two weeks later: sorry, the video got taken down---here's a still shot--
each of the dads is claiming "I am your father," like Darth Vader:
But almost 7,000 viewers felt otherwise:
Via Lee Wind's blog I'm Here. I'm Queer. What the Hell Do I Read?: Gay Teen Books, Culture, Politics, Social Justice, Equality, GSA Info... and More!"
[I think GSA = Gay Straight Alliance, not General Services Administration.]