As I see the story, if you trust in someone so much , you have a relation with him even without asking ( you go in dates, you have relations, she/he help you all the time, and then he tells you he was fucking other people in the same kind of relation like you have with her/him, you probably get piss off so much, no?
That person lied to you, that person wasn't honest at all, I think the girls get mad for something.
Maybe you could ask "Why they fuck together the MC?" well, I have an explanation for that for the end fo the game.
If you want to know I have no problem to do a spoiler in another comment.
		
		
	 
The ending of each girl took me by surprise, 
but what would have happened later on if the player had only explained about his deceased friend (the other dialogue), and later on after he resolved what he went to do at the mansion, 
upon his return he said that he was going out with other people, would each character's route have ended differently? 
Since your game always ends up having the possibility of changing the course of the story, do you plan to do something like that? Have another possibility of finishing the route of the first characters without them simply disappearing like in a bad ending?
 I think about this because during the last endings, 
about ursula: the player promises to talk about his past to her At the very least, someone wouldn't ask for better explanations than "
we had fun together" Even if they feel betrayed, they know what they feel for the character and by following each one's good route they would have an idea of what their personality/behavior is like. .  (Ursula, especially after her ending, knows that there is something wrong with the player and Mr. D 
to the point that she knows the player could do something dangerous without telling her his real intention to protect her from Mr. D ), 
About Rachel, I could be wrong, but that explosion he had with her about her complaining about her personal problems having a lot of stuff, he mentions about his problems about the past. Among these things (if he chooses to talk about the past without mentioning the other person) 
would it have a different ending with the characters? 
something after what comes next in the next update. (the player has the option to say he will return safely) but I know that depends on the course of the story. he would return to the city after everything .
 (I'm sorry if this is a stupid question or if it displeases you I really enjoyed the game. )