>tfw no childhood friend lamia gf
Consider that Dr. Cthululy said no "misconduct" (she's pretty much telling the Lamia to keep her hands off him, her boytoy)
And even if they didn't have proper sex, (by the dialogue here, I think it means she lays eggs, though this will be debunked if we ever see her have a navel) it could very well be possible she did something to him in his sleep or did something to artificially inseminate herself, assuming she ever got a hold of a napkin or tissue he "used."
@nobaka