Once upon a time, we thought that the babydaddy mystery surrounding Kelly Taylor's love child on the new 90210 would be the "Who killed Laura Palmer?" of the CW set, with Jennie Garth given mysterious, clue-laden bon mots to drop all season, then a hasty denouement revealing Kelly's torrid night of cappuccinos with Nat at the Peach Pit five years ago. Then, producers threw us for a loop, stating that Shannen Doherty would reveal the big secret as early as tomorrow night's episode when Brenda confronts Kelly about dating the hot hipster teacher at West Bev. Now, in the wake of that hint, a tipster has informed us that a Canadian ad for the big episode may unwittingly supply the father's identity. Spoilers, after the jump...According to tipster "Lezzy McGuire":