Was it Giles' grandmother or grandfather?
Grandmother. "I was ten years old when my father told me I was destined to be a Watcher. He was one, and his mother
before him, and I was to be next."
I like the idea of Gaith and arguably we may finally get it in the comics?
Have you read season 8?
Remember Faith is the 'do that' girl who thinks that friends are there to sate her carnal desires so if she thinks Scott's cute there's only one thing on her mind? Remember Faith also puts the moves on Robin Wood and Spike. The girl can't help it
Scott wasn't Buffy's boyfriend and Faith didn't even know that there was anything between him and Buffy. She didn't make any moves on him that we know of after he started dating Buffy, or after he dumped her.
Faith flirted with Spike long before there was anything between him and Buffy (season 4) and she put the moves on him in Dirty Girls
before she even learned about his and Buffy's history. Leaving aside the question whether Spike could be considered Buffy's boyfriend at that point, if Faith wanted to go after Buffy's boyfriends, Buffy's jealous reaction in Dirty Girls
would've made her want to go after Spike more. But instead she didn't try anything with him after that and hooked up with Wood instead.
Wood was most definitely not Buffy's boyfriend when Faith met him. Buffy had only flirted and went out on one aborted date with him a while before, and neither of them pursued it since Buffy obviously still had feelings for Spike and Wood was smart enough to notice. And Faith didn't even have any idea that there had been any romantic interest between Buffy and Wood. Buffy doesn't have proprietary rights over every guy she's ever flirted with or tried to date.
Bottom line, Buffy and Faith might just have a similar taste in men, but it's really not like Faith has been targeting Buffy's boyfriends, like a jealous sister who wants to get one over Buffy. She did try to steal Buffy's boyfriend in season 3, but only after she went bad and the Mayor told her to make Angel evil and get them on her side. Riley she did 'steal' and that was when she was trying to steal Buffy's life. But reformed Faith in season 7 didn't try anything of the sort - she was even uncomfortable when she was named the leader instead of Buffy.