I think we should re-instate here that the refuge vows are not based on "NOT HURTING OTHERS" exclusively, the bias conclusion from that posit is that, as long as we do not hurt others, it is fine, and we can bend or brake the vows. No, I don't think it is like that.
Refuge vows are based on "REFRAINING FROM SELF-DESTRUCTIVE ACTIONS."
And indeed, hurting others is definitely a self-destructive action, but self-destructive actions are not limited to that aspect only.
This becomes a hot topic when we approach sexual mis-conduct, and instead of bending the vow with a bias logic over it, I think one needs to humble down a bit and seek knowledge and advise.
If one's Guru's advise is that it is permissible to engage in homosexual relationships, I think one should still contemplate this and not take this as a "waver from above," indulge and tell everyone else that it's "ok" to have this or this sexual behavior (for this may be misunderstood also). Maybe the advise was not meant for everyone, and certainly it was not meant to contradict any of the refuge vows in any of its nuances.
Sexual activity, heterosexual or homosexual works with EXACTLY the same dynamics.
Never mind which hole we use (excuse my language), the attachment is just as dangerous.
Those of us that are attractive and often face situations where it is just easy to engage in sexual activities without anyone knowing about it will know how hard it is to remind ourselves of Dharma and vows there and then... And this works the same M/F - F/F or M/M.
That is a discussion topic that I would find more interesting actually, or at least more constructive.
What is at stake here is our enlightenment, not the acceptance or rejection of social behaviors or sexual preferences, that would be irrelevant.
And I do not think that the Buddha ever said "homosexuality is bad and evil", yet I am certain that the Tatagatha said that attachment to sexual behaviors or compulsions are self-destructive.
There is a reason why monks are not to engage in ANY sexual activity.
My 2 cents of thoughts.