Nate Halliwell/Alternate/Season 5

A Whole Different Reality
After Jared changes a certain moment in timeline, it changes everything for the Destined Ones lives, mostly with Wyatt, Chris, and Prue. Nate gets extremely worried about this different Prue as she is a different Prue. From another reality. He voices his worries with Ella and also his good friend, Johnathan, about it. As Prue seems to be distant from him, and is not sure why, and does even want to get close to their son, Andrew.

Jared Succeeds On His Plan
With help from a potion from Melinoe and a spell, Jared is able to distract Prue from fixing the new reality he made causing her to lose herself into the currently alternate reality. Nate is in shocked but still accepts and Prue eventually delves into her life with Nate. This cause Jo to be erased from existence. After a good while, whenever Prue tries to have sex with Nate, nausea happens. Nate wonders what is wrong. And Prue is not sure either.

Prue's Memories Are Restored/ Nate vs. Wyatt
Knowing that Prue shouldn't keeping Nate away from the truth anymore, she tells Nate the truth of another reality where she is married to Wyatt. Nate still can't believe and continues to believe that Prue is delusional. And because of this, Nate gets into a fight with Wyatt. Soon later, he also realizes that Andrew is not his son, but someone else, due to this alternate reality.