Not quite "two lovers can do no wrong" but one of my very few "favourites" in the bible:
If I speak the languages of men and of angels, but do not have love, I am a sounding gong or a clanging cymbal.
If I have the gift of prophecy, and understand all mysteries and all knowledge, and if I have all faith, so that I can move mountains, but do not have love, I am nothing.
And if I donate all my goods to feed the poor, and if I give my body to be burned, but do not have love, I gain nothing.
Love is patient; love is kind. Love does not envy; is not boastful; is not conceited; does not act improperly; is not selfish; is not provoked; does not keep a record of wrongs; finds no joy in unrighteousness, but rejoices in the truth; bears all things, believes all things, hopes all things, endures all things.
Love never ends. But as for prophecies, they will come to an end; as for languages, they will cease; as for knowledge, it will come to an end. Now these three remain: faith, hope, and love. But the greatest of these is love. - 1 Cor 13
So, "god" forbid your bisexual friend was holding love in such a high regard.