Threesome = all parties involved. Then they bathed together.
Canon, umm okay yeah Angelus ACTING bi (kinda gay) isn't proof? The statement was off hand anyway (why am I still posting)
Oh and Joss actually said that Spike and Angel DID have sex in hole in the world's commentary, if you are still doubting that is canon.
Still doesnt mean THEY had relations while he pleasured them both.
The ONLY facet from that scene about it is that he had them concurrently, BUT that does not say he had them while they had each other.
Threesome means three parties enjoy it at the smae time, DOESNT mean they have to play all sides....two heterosexual guys were with one woman, that is still a threesome, and she is pleasuring both man at the smae time, however these two men wouldnt touch each other sexually.
Until the DVD Special Edition deleted scenes show otherwise, you cannot prove they sexually enjoyed each other.
Like has been pointed out, Joss didnt confirm it, he teased it, as he has teased many many things about the show, fact is, his words can no longer be taken as canon until the end up on film or in print, as he often makes ludicrous comments....
So with all that, i can say, there is no evidence to prove any of these characters were Gay or Bisexual.
In the tone of the thread, it would have been fun if there had been a little more in the did they or didnt they thing.