How sex as a biological phenomenon is divided up into concepts is entirely *cultural*
One of my cultures has historically had 4 sexes + 2 more variations on M/F (+1 of those with 2 subtypes)
But please remember these are *both* Anglo-Western conceptualizations in these discussions.
But these are not the only two possibilities.
If we subscribe to these being the only two possibilities, that erases *all* non-Western and/or Indigenous sex systems.
This is primarily THE reason why I do not prefer any of those terms wrt myself, and this is a not uncommon view.
That is because of how history has played out wrt oppression...
This is probably not the most coherent thread, but I have strong feelings and also don't very much want to discuss this topic (very painful experiences), but I felt like I had to say something.
"Third sex" also heavily implies the usual priority order of 1. M 2. F 3. intersex.
Somehow it's never the "first sex" or even second.
At least "intersex" doesn't have this implication. Just a form of between-ness (which can be separately discussed)