It seems to me to be less about homosexuality and more about obsessive heterosexuality. A want to be nearer to some unrequited love object to the extent that one grows a sexual interest in their significant other by proxy. The third in the "three way" is figurative, it's the concept of the female, not the female herself. It's the extreme of the "you are having sex with everybody the person you're having sex with has had sex with." In other words, it's wicked romantic.
It seems to me to be less about homosexuality and more about obsessive heterosexuality. A want to be nearer to some unrequited love object to the extent that one grows a sexual interest in their significant other by proxy. The third in the "three way" is figurative, it's the concept of the female, not the female herself. It's the extreme of the "you are having sex with everybody the person you're having sex with has had sex with." In other words, it's wicked romantic.