I was specifically referring to the whole "You have a remote mission supporter who, as she is corrupted, starts giving handjobs and blowjobs and even riding dick while still in the support role, and you have a screen that shows her" thing. But I may give Nebel Geisterjager a try (I think I downloaded it before but grabbed a 100% save and just watched the scenes, I may give the actual game a shot this time).
Nebel's biggest problems are its too grindy and difficult to trigger all h-scenes.
The basic play of that game is you explore haunted houses and fight ghosts. Your gf and your boss fight in the real world while you fight in the spirit version of the house.
You can't see them or anything but you can call her often and talk. Have to help guide her thru diff areas by unlocking stuff in spirit world for her.
As she fights enemies her heart rate goes up.
If she's struggling her heart rate spikes.
If she's defeated she has to rest.
In the resting room her heart rate spikes for other reasons.
You can't see any of this, can call her to check in and if you call during harassment scenes you'll stop her and save her.
If you don't you'll just get updates on her sex experience.
You can install cameras around the house in the spirit realm and watch what happens too!
Similar to Solgante you have fuzzy cameras (but later get HD cameras that are clear.)
Similar to Solgante after missions you can call/find her around town and she might be cheating (but you can stop this if you're fast enough!)
I want to say it has 5 endings?
Definitely too grindy but with a bit of fixing I'd say this is the perfect NTR experience.
If I knew someone who could code the game I'd definitely script write and voice act for another :l