The NTR scenes are so formulaic lol. It's like they're following a set script for every character. NTR 1: No pen (heroine hates it), NTR 2: Pen (heroine starts to like it), NTR 3: Heroine submits to the other guy, NTR 4: MC discovers that he is getting NTR'd and starts to like it, and the heroine changes their mind and wants to break up with NTR guy, NTR 5: MC goes full cuckold mode and even helps the other guy to fck the heroine willingly, sometimes even asking the heroine to keep doing it.
I've viewed All NTR scenes except Kirara and they all went that way.