tftnt
I don't think Xander ever consciously did anything like that. He spent lots of time single, so if all he wanted was a girlfriend & he was keeping Willow around for if he could get someone better, then he would have been dating her pre-season 1
I hate the cheating in s3, but I think the both of them were just confused. They'd been friends for such a long time, they really cared about each other & they were teenagers in these life & death situations a lot of time. Don't get me wrong, I
hated it so much, but they did both pay for it afterwards.