3. Heterosexuality, homosexuality and bisexuality.
Asexuality is the lack of sexuality and pansexuality is literally the same as bisexuality. 'Pan' is a greek prefix meaning 'all', but as there are only two human sexes it's the same as 'bi'. 'Pan' would make sense if there were 3 or more sexes.
I don't get the etymology for pansexual, though; isn't it panSEXual not pan-gender attraction? there's only two sexes; male and female. at least that's how I read it.
Pansexuality is the worst (non-existent) sexuality ever.
It means you're attracted to any person regardless of gender, which is literally the same thing as bisexuality (being attracted to two or more genders) just differently stated as a "definition".
Only SJW identify as it instead of bi to be seen as edgy and ****.
Asexuality is most likely some sort of a mental disorder rather than a sexuality.
Then there are some made up sexualities which are a reach but I'm not bothered (demisexuality, etc.)
So, three.
I hope you're not gay or you have a "mental disorder" as well, it seems.
There are four.
Gay
Straight
Bisexual
Asexual
All others are fake (akiosexual, lithosexual, cupiosexual, etc.) or just pretentious ways of saying the other four (pansexual, polysexual, omisexual, etc.)