One of these days we can get past the "but we're both girls!" trope.
I go back and forth, about that trope. Sometimes it's cute, but other times, it gets annoying, especially when it comes late in a series. When you're 20 - 25 chapters in, and the MCs have already had a few romantic moments, together, then one of them suddenly busts out the "but we're both girls" line, all I can think is argh, I thought we had got past that stage in their relationship. I think the author is just using the trope, to prolong the series, at that point.
Um... I understand, kind of, the trope about "how do two girls have sex?" But "how do two girls kiss?" I mean... put lips together... that's pretty universal, right? It's not like male and female lips are different, other than the potential for facial hair... (There's a higher potential for facial hair with men, but that doesn't mean there isn't any with women...)