All the ships that have any traction have moments fic writers point to... To justify their ship. I see it as pointing to flexibility of mind but although i write slash, there are only a few same sex ships or sexual interactions for which there is real canon evidence -
a) confirmed in canon, (willow and tara, willow and Kennedy)
b) referred to by one or more of the parties (Angel & Spike) "that one time" (and a groupsex refeeence in Angel i cant trace right now)
c) confirmed by Joss: Ethan and Giles (which can also be logically inferred from Giles mentioning orgies at which there is only one woman)
d) suggested by logic - Andrew and Jonathan in bed together, Andrew's repeated dreaminess & super-attachment to men in canon (Warren, Jonathan, Spike)
note: i see *no* evidence for reciprocity other than Jonathan (probably) - but situational same gender sex does not make people gay, just desperate ex. prison sex. Pretty sure Andrew is gay. Jonathan could be gay or bisexual or heteroflexible. Warren is simply a sleazoid predator.
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Justification moments (no actual proof but in a couple instances you can see why people see it)
Xander ( Angel or Spike)
He expressed "verbal appreciation" of both Angel and Spike as attractive. While not confirmatory, it is a bit unusual for a man to express verbally the attractiveness of other men.
The early references are probably before they decided that Willow would be the gay one
Buffy & Faith.
There is a physical intensity to their fights and some of their conversations that feels very sexual - especially to thoae who want it.
Giles and Ethan
Years before Joss said it, their in your face 'i wanna kiss you violently ("have sex with you" very hard) arguments/fights. There is one instance if they filmed it today, i am sure they would have kissed.
That conversation in the restaurant where Ethan appears to flirt with Giles before we realize there is a waitress he is hitting on - feels very much as if the director is "showing while hiding" the reality.
Vampires
More in Angel than in Buffy there are allusions to group sex between Angel, Darla, Dru & Spike. There is no reason to believe vampires care about human conventions - they have the code of "want, take, have.' Not neat morality boxes made by a society that wants to kill them. Excluded groups often indulge in more extreme behaviour because they feel they have nothing to lose. Vampires add power of being top predators to that outsider mindset. They are outlaw.
I personally dont believe vampires are forced to be exclusively straight or gay unless they really want to be. As violence is the rule in vampire society, "mastery" (rape) by the dominant over the less powerful (any gender) would likely be common as it is in places like prisons and to a degree in militaries over history to the present.
