midwesterner: thanks!
zeeskite: The forbidden relationships are sometimes divided into the ones that are because of familial relationship and the ones which aren’t. That is called shear basar. ??? ???.
The only time I have seen its relevance, is in the shittah of Rabbi Akiva who held that chayvei lavin were ?? ????? ??????.
That is, that some women who are assur to you, if you do kiddushin to them, the kiddushin does not work at all, but some, the kiddushin works and you are just still assur to them. There is a machlokes which issurim this applies to. We pasken that it applies to most chayvei krisus. (so like not nidda).
But, Rabbi Akiva held it applies even to chayvei lavin. There is a machlokes in the gemara exactly what Rabbi Akiva’s opinion was, and according to one opinion, it only applied to chayvei lavin d’shear. So not almana l’kohen gadol, but yes anusas aviv, if I recall correctly.
In any event, I have no reason to think it has any application to this halacha here, and I was just negating a possible silliness.