"Oh, my nails... good thing we didn't have sex"
This is the most relatable thing I've ever seen on a yuri manga.
Hehehe, I know. Recently, I see this a lot.
There was a time, yuri authors didn't care about such details. The stories were about the romantic feelings a girl could have for another girl. And if the feelings were returned, then we would see a kiss scene -- or maybe even a sharing-a-bed scene that hinted at sex without showing too much. That was about it.
In recent years, things have changed. Both the authors and the readers have a much deeper understanding of the real life issues a lesbian relationship entails. Also a much better notion of how lesbian sex works. That's why practical details like the problem of having long nails tend to appear way more often in yuri manga now.
(I think the first time I saw this issue tackled was in Sweet Guilty Love Bites... the MC, who was a hostess at Club Lilac, took a homeless girl to her apartment, they started chatting, and then this girl suddenly said "Oh my, Miss Hostess, look at those nails, you can't even masturbate like that! Since you've been so nice to me, let me repay you with my fingers and give you a few orgasms!" Lol.)