It's an older game, think it came out around 2012-2014, and it has a partial translation here.
Its an RPG Maker game where you play a female, it tracks your sex stats, become corrupted letting you do more and more lewd things, you can optionally attempt to hide your 'sluttyness' from your childhood friend who has a crush on you, and you can get pregnant (not sure if it has birthing or just "you've got a baby").
I may be mixing up the very beginning of the game, but I know after this you end up in a sewer or basement area attacked by thugs/bandits/gang members. Your childhood friend attempts to fight and gets beat, so you start combat -- you lose you get raped in front of friend, you win you stay a virgin. At one point early(?) in the story you need to meet a guy at the inn for information, you get some options like "let your friend follow", "tell him you'll go alone" (example of the NTR aspect), then at the meeting you get some options that lead to you either leaving, fighting the guys (lose = gangrape), or submit (gangbang).
The game is Sword Princess Cistina.