Jennie Garth and Riley Thomas Stewart in 90210 by Michael Diamond Desmond/The CW Jennie Garth and Riley Thomas Stewart in 90210 by Michael Diamond Desmond/The CW

Well that mystery sure didn't last long.

While many thought that 90210 would hedge its bets a while and leave viewers guessing as to the identity of Kelly Taylor's babydaddy - perhaps at least until an Ian, Jason or Luke could be coerced into paying the CW's reboot a visit - sources confirm to TVGuide.com that lil' Sam's pop will be ID'd in the fourth episode, airing Sept. 16.

That doesn't leave much time for the Name the Daddy Sweepstakes, which commences... now. Will it be Brandon, Dylan, Steve or someone else? Cast your vote here, then claim bragging rights on Wednesday morning. - Matt Mitovich