I guess Lex is starting to reach a threshold where people don't find her face attractive anymore, S3 spend too much time focusing on Lex and Cass and little on the Cheerleaders they were suppoosed to be getting "Revenge" against until now, It's weird for Sarah to go from being fatphobic when Lex was first blowing up to saying things like "I wish I had the curves to fill out a dress", She's really handsy with them too considering she has a boyfriend already. Also the time jump from the weekend at Cass' to the prom and not even a hint at the Dad subplot, did Lex's dad just let her comeback home twice as heavy as when she left and didn't ground her again?
People being impatient S3 does seem to actually fulfill sequences, The Cass dress is exactly the same as in her comic with the other goth girl so his previous images of the Cheer Squad will probably come to fruition (not sure about Stacy getting pregnant though).
S3 just finish up the 2nd half quickly it's getting a little long in the tooth with Lex and Cass