Boku no Risou no Isekai Seikatsu 3

With the collar of servitude removed, Chise can now use magic, and Norn, wanting to see it, takes her outside.
Chise's magic is a perception-inhibiting spell that prevents others from noticing her presence.
Taking advantage of the fact that no one can see her, Norn takes off her clothes and becomes completely naked.
Then, sneaking up behind the bewildered Chise, Norn lifts her skirt and tries to have sex with Chise right there.