I know they were originally the human children of two different couples who were close friends but I am like 60% sure no explanation is given for the dicks so we may come to our own conclusions there.
I like the idea of a cumslut tongue piercing, and it could be something given to you by a dom with a reduction-over-time addiction mechanic, like Luca or upcoming Jasvalla, but you keep the item after weaning yourself off of them specifically.
Some nice little touches would be Breast Immobilization similar to Ball Immobilization, Nuki Nuts but for milk to help facilitate Immobilization and a fluid-changing set of underwear that become transparent like the Honeypot Bra with high vaginal wetness or cum production. I was actually...
This leads me to several sexy ideas, actually. What if you could set up Ev and Carmen, with their shared interest in virgins? What if you could offer Ev companion virginities, like Cait's anal virginity and Ryn's penile virginity?