Everyone and Alejandro

Bridgette
In Aftermath: Bridgette Over Troubled Water, Bridgette is shown to no longer have any feelings for Alejandro and apologizes for ever kissing him.

In Aftermath: Revenge of the Telethon, she joins along with LeShawna in Sisters.

Duncan
While Duncan is away from the game, Alejandro insults him when talking to Courtney in an attempt to make her dump him. Once he returns, Duncan discovers Alejandro's antagonism when Owen tells him what Noah had told the team about Alejandro before his elimination. He and Alejandro have a rivarly throughout most episodes, which turns into a conflict once Alejandro tricks Duncan into getting attacked by Ezekiel in African Lying Safari, causing his elimination from the game at the hands of Heather and Alejandro.

Noah
See Alejandro-Noah Conflict for more information.

Tyler
Despite making an alliance with him in I See London..., Alejandro votes Tyler off with no remorse in The Ex-Files, even though they had agreed to vote off Duncan together.