On the season finale of 90210...
... Ryan learned he's the father of Jen's baby, but she didn't want him to play a part in its raising. He responded by driving very drunk, running over the West Beverly sign and and seeing Mr. Cannon pull down the shade in his classroom late at night. (More on this below.)
... Jasper set fire to Liam's boat because he saw Liam and Annie bonding on it, as viewers saw and heard Annie confess to Liam about the hit-and-run. Liam responded by beating Jasper to a pulp, while Annie went home and told her mom and dad the same. Earlier, Deb and Harry basically admitted they didn't love each other.
... Dixon and Ivy made up and Dixon planned on going to Australia. However, Deb forbade it after she learned of his gambling problem. As she and Harry fought, Dixon snuck out of the house.
... Adriann and Navid got back together, after she discovered the braclet he gave her. But Javier wants to fight for Ade's love and invited her to open for him on a year-long tour.
... Silver admitted to Teddy that she does love him, forget his father!
... all alone, Naomi ended up in the classroom of Mr. Cannon. He thought she actually wanted him and didn't take no for an answer. The last scene of the season was Naomi's face, as Mr. Cannon, we'd imagine, forced himself inside her.