An unnatural sexual attraction to homosexuals, reguardless of their or your gender. For example, a lady-wanter who would rather watch lesbians have sex with each other and with himself, or a fellow-wanter who would rather watch men have sex with each other than with her. Or a bisexual who likes having sex with their own gender but would rather watch the opposite gendescrew each other than him/her. Or just generally finding gay sex or gay people way hotter than the rest of the planet.
Not to be confused with homophilia, which technically translated would mean "powerful or unnatural sexual attraction to someone who is the same as them, for example, the same gender", and, um, there's already a word for that. Possibly more than one.
Percieval suffers from advanced homosexiphillia; he can't get laid because he is only attracted to lesbians.