Is it possible to avoid scenes of the girls having sex with other guys in this one? I see there's a preview image of one of them and a green-skinned dude.
		
		
	 
As an NTR and sharing hater, let me just say, "Dont worry about it".
The short answer is that there are a few unavoidable scenes that feature other dudes, but please do not judge it off of that because you'd be missing out on one of the best games on this site. You play as an evil guy doing evil things, and your character sees the girls as disposable, but that changes with time.
The long answer is that of the girls you might consider "yours", theres only one girl (who is basically a side character) who has unavoidable content with another dude. The specific scene you mentioned is actually not a sex scene, you stop that guy from raping her in that scene, but you end up having to give her to your psycho king who you are working to kill. It a pretty good plot point because you end up seeing how nuts the king is and establishes his abuse of power. It also goes to show how evil your character is because the girl is pretty much entirely unwilling the entire time. I think its also worth noting that in the early game, the MC has absolutely no romantic interest in the girls and that he undergoes some pretty thorough character development and becomes more interested in and possessive of them as time goes on. It doesnt present the scene as NTR or even sharing, its just something that has to be done or else you'll be executed. You also take her back from the king a few chapters later. Any other scene with another guy and a main girl can be avoided.
Take it from me, I hate both NTR and Sharing, but its not that bad and the rest of the game makes it worth it. 
P.S. I don think you were asking about this stuff but I thought I'd include it here just in case. There are also a couple of background girls you see having relations with other guys. They have almost no impact on the plot and are not involved with the MC in any way. theyre literally just set dressing. For example you see a police chief screwing a woman you've never met. There are also some people fucking in bathroom stalls that you see. There are a couple of scenes where the MC transforms and sleeps with people looking like someone else...
Oh and there are some unavoidable scenes with tentacles and some unavoidable lesbian content but thats it.