There isn’t yet (just regular cunnilingus with a teacher and licking the nurses tits and armpit post-sex)
But yea, I think a lot of NTR-focused players are waiting for Rei (and much of the cast) to be conducting netorase activities more openly around or towards the MC (to the point that they and the MC both know and embrace it, but both pretending otherwise. [eventually leading to full “cucking” after a while]).
Right now, there’s just a bunch of netorare (with light netorase), but once/if the main love-interests start directly involving the MC in their “cucking,” we’ll probably be getting a game similar in popularity as early-nympho priestess.
Would be cool to see Rei and the other women (like the nurse) asking the MC for a “favor,” and making him eat them out (after they had sex with someone else) while they pretend that nothing happened prior to the cleanup.