With all that has been made of Lily's past on Gossip Girl, ever wonder who exactly Serena and Eric's father is? Presumably, he was one of her three husbands before Bart.

Looks like we're going to find out for sure - and on two shows! According to reports, Gossip Girl is set to introduce Serena (Blake Lively, below) and Eric's father, Keith, on the spinoff episode May 11, which introduces us to young Lily in the 1980s.

Matt Barr (of One Tree Hill fame) will play the young version of Keith in the flashback episode. Then, Keith going to be making an appearance in the present day next fall in Season Three of Gossip Girl! Who will they get to play him is another story.

Speaking of Lily, her love child with Rufus is scheduled to return in May as well, although his reasons for doing so remain a bit of a mystery to even ardent spoiler hounds.

Comments and theories welcomed!

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.