Seeking Girlfriend does the NTR

[Arktos]

I'm looking for something quite unusual. Essentially where the protagonist's current love interest is actively involved in NTR-ing other harem members.

This can either be directly (i.e. futa or lesbian), or by setting up the situations for harem members to be ntr'd.

examples include Trouble In the Arena, where the demon maid fucks a number of love interests, or Sphilias Familiar, where a harem member gives the ugly bastard his magic cock, so he'll destroy her competition for the MC.

 

[crnisl]

An interesting theme. Have you already played A Promise Best Left Unkept?

There's also a bit correlating concept which can best be described as a girl hates another girl because she is either jealous, they are rivals in love, work, etc so she gets someone else to fuck the girl she hates in order to beat or humiliate her - or get theguy for herself, like you are requesting.
There was a good quality

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hentai manga. A girl delivered her tennis rival to her bull bf, then she set situations for all the kinds of gangbangs for the rival, etc.

 

[Sir Gary Bummer]

I got the inspiration myself from The Keymaster, so you can check that out.

 

[Arktos]

Didn't expect the developer himself to respond. Your game is great. Thanks for the recommendation. Bit concerned about the unimpressive rating, but I'll give it a go.