The topic made me remember a documentary I watched some years ago, about a butchlesbian and a heteroman that had fallen in love with each other despite their sexual orientations that remained unchanged.
They had started out as friends, that in time became tighter and tighter until they realized, that they had actually fallen in love with each other.
However, as she was a strict lesbian, she could not find him sexually attractive, and as he was strictly heterosexual, he could not find her attractive either as she was too much of a guy in his mind.
Despite this, they had no problem with a certain degree of intimacy such as cuddling and romantic evenings, while the more "physical" part of intimacy they had solved by finding ways to please each other with, such as massage, plays with various tools and in short just intimate nearness but without the actual sexual part.
I strongly believe that while the sexual orientation is generally biologically fixed since birth in a person, everyone yet has the slumbering ability to potentially "fall" for someone regardless of gender/Sex.