Read at the end of '13 or sth. Brother-sister romqnce mostly.
What I remember: Large family reunion during winter. Immediate family has Two brothers, two sisters. half/step most prolly. Story is told from youngest girl's POV. girl falls for closest older brother during reunion. they discover other two siblings also doing unsiblingly things together. strictly monogomous though. has dilemma after coming back home. starts seeing classmate/football star. Tony iirc (weird huh!). regrets and comes back to brother. gets discovered by parents. family understands. two sisters get pregnant by respective brothers. happy end of story.
Some more info: I mostly remember 4-6 chapters. could be more or less. I rember googling the writer's name. has a lit account by same name. although by the time I read the story on xnxx, her last story on lit was 2-3 years ago. so already inactive maybe.