Season six has really ended differently here. Hopefully it's logical that fatherhood would change Xander this much. He can't just sit back and wait for Buffy to take charge like in canon because he has a daughter to protect. And with a second family (Xander and Bonnie and Spike), Tara is not going to be as quick to go back to Willow.

Yeah, I don't write the two boys instantly falling in love very damn often, do I? Trickster was the closest I came to that, and Xan, childe of Nusa didn't fall in love with Spike as much as he just fucked him raw.