I'm pretty sure Demonio's original self was an adult man already. He's just in a teenager's body now. Gotta check chapter 1. He's just so infatuated with milfs that he lost the sauce because the teenage protag likes the teenages girls lmao
I think she might like how he looks squinting. Or spooked. It happened last time and she blushed like mad. Well he was also like 2 inches from her face...