Okay, let's theorise about azure
Or, Melanie attempts to justify BioWare's lazy biology
So, we all know asari have something analogous to a vagina - though it clearly isn't a vagina, so for clarity's sake I'll use the slang 'azure' to refer to it (sidebar: it's pretty weird to have a fancy brothel just called 'PUSSY') - we all remember that bit in ME3 where Samara walks towards the camera with the whole thing just fully on display because the developers are perverts who don't understand how armor should work.
ANYWAY
Asari reproduction, unlike that of most other species, doesn't require sexual contact. They do it with their brains. Given that they have breasts, we can assume they're mammalian and give birth to live young, so that's what the azure is for biologically: squirtin out the babby. So that all makes sense, but it's complicated by the fact that asari clearly have physical sex for fun, so touching (both outside and inside) azure feels good.
Extrapolating from that, we can assume the pleasure response is just an evolutionary gift, similar to the human clitoris: the button that makes you feel good™
So what does this mean for asari sex? At this point, we can start making Wild Assumptions based on what we've already theorised. Asari relationships with krogan are clearly common enough that nobody bats an eye about the size difference, so let's assume azure is much more flexible than a human vagina - Thessian evolution is clearly much more concerned about its birthing races not suffering during childbirth. As for sensation, since it's similar evolutionarily to a clitoris, azure stimulation just feels like that all over.
Maybe we can also throw in the possibility for a genetic mutation or two - arousal causes the azure to stretch internally in anticipation of having fingers pressed into it, but a rare mutation causes this to happen externally instead. Is this an excuse to make asari with dicks canon? You can't prove it is. I still haven't come up with a reason for them to have balls, though.
Of course, this is all conjecture. I like it as a personal theory, and it's the basis I'm going to use for writing asari sex in future, but more than that this serves as advice for anyone inventing non-human races to think about everything. The design document for asari just says 'sexy blue space women with squid heads' and as a consequence I've had to write up all of this unscientific nonsense to justify their weird biology. This all could have been avoided if anyone in the design department had stopped jerking off for 30 seconds to think about how this all worked!
I re-read this for the first time in ages and 'squirtin out the babby' made me snort, I'm glad I can make myself laugh
It's feel good™ that gets me. Though, I offer an alternative reason for Asari with dicks: Culturally they've accepted that gender is bullshit, and their medical science has reached the point where they can have any genitalia combination they want for as long as they want. Since Asari can live for centuries, this has led to having a penis being something akin to getting a piercing or a social identity, like being Goth. Sometimes they stick with it, sometimes they try it for a few decades and move on. Asari with dicks are so common place, they're basically treated the way tattoos or breast implants are nowadays. A few reactionaries scoff at them and everybody else just nods and moves on with their lives.










