[Request] Need help finding an incest story I’ve read before

I’m looking for a story that I read a year or two ago. It was either on Kristen Archives or Literotica. Here’s everything I remember about the story (sorry if it’s a jumbled mess.) It was between a brother and sister on one of their birthdays (I believe the brother) with a group of the sisters friends as well. The general theme in the beginning is all of the girls want to thank the brother for all that he has done for them. For example there is some back story about how he went to a frat party with one of the friends and had to drag her out and drive her home to protect her. A little about the girls, I remember one of them was dark haired and enjoyed being dominated. She is also the only one in the story to take anal. Another one is very shy but surprises everyone when she show up wearing a tight dress and makeup. The shy girl was picked on by the sister and her other friends until she met the brother and told him there was a group picking on her. The brother talks to the sister and the shy girl then gets invited into the group. There is some lesbian shower stuff somewhere in the story as well. During the party they play a game with colored marbles in a hat. Picking a certain color (green or yellow I believe) would mean you had to take off a piece of clothing. The brother and sister don’t have sex until near the end of the story. I’m not sure if I remember the end of the story correctly but there may have been something about the guy marrying the shy girl later on. I’ve been trying to find this story for months but I guess my Google skills aren’t good enough. This is my absolute favorite story I’ve read please help me find it again. Thanks.