To not automatically reject Zoey, there's a behind-the-scenes check that looks at these items:
- Mad at Zoey or not (Ep 9 choice): +3 score if not mad
- Derek or Zoey better friend (Ep 9): +1 if said Zoey
- Offer to let Zoey crash in your room (Ep 9): +1
- Photo with Zoey (Ep 9): +1
- Zoey in top 3 for costumes (Ep 9): +1
- Said not okay with Jacob going after Zoey (Ep 10): +3
- Hung out with Zoey in Ep 10: +2
- Gave Zoey hug (Ep 11 choice): +1
You need to have at least 8 points from the above (and for people on MJ path, not told either you love them) to have the option of Returning to Zoey rather than Rejecting her. The Rejection if you have the choice is also different than the automatic one.