If two sapphogender folks fall in love with each other, their attraction is to women, what happens? Are they women for each other but not for their ownselves?
Well, firstly you should probably be asking someone who actually is sapphogender and not me. The most honest answer I can give is “it’s up to the individual to define themself and know what’s most comfortable for them.”
But I should probably clarify that people with these affinitive genders do not necessarily have to identify with labels like man or woman; they could be any man/woman-aligned gender or any FIN/MINgender. The important thing is that (for sappho- and achille/vinciagender folks at least) they identify with the terms wlw or mlm, but outside of this, they wouldn’t really describe themselves as ‘w’ or ‘m’. It’s also worth mentioning that sappho- and achille/vinciagender people don’t have to be exclusively wlw or mlm. They could also call themselves nblw/m and be attracted to other genders as well.
If I could talk about my experiences as achillegender, I would say that:
If I were ever in a relationship with another achillegender person, it would largely have to do with how “achillean vs diamoric” we considered our relationship. I only find that my connection to maleness becomes relevant/important to me in the context of being attracted to men. My gender doesn’t change, I just kinda...forget that it’s there. So if the person I'm with and I can both agree that the mlm aspect of ourselves is not really present in our relationship, then we would remain seeing each other and ourselves as nonbinary. But it really just depends on the person.
You ask, "Are they women for each other but not for their [own selves]?" Again, sapphogender people don't have to identify as women to be sapphogender. But what's really important to understand here is that identifying as an affinitive gender is, as with any gender, a deeply personal thing. Like, I'm not a guy "for" my husband, but deep down I'm really nonbinary. I'm nonbinary to everyone I'm out to, but deep down, having a boyfriend, being married to a man, and feeling attraction to men makes me feel...guyish. And the only people I'm really comfortable outwardly acknowledging my "guyishness," no matter the context, are the men I have emotional relationships with? I can't really explain why, I just do.