A World of Cubby Sex/Male Teen/Skunk/Weekend/sister
Your sister is a 13 year old bunny your parents adopted. She was the daughter of a good friend of your mom's after he and his wife died in a car crash. With no family your mom and dad took her in and raised you together though you knew full well you weren't related and ever since the age of seven have been playing sexual games together with parent approval. Your parents never joined in but they didn't mind it either so long as you kept it private and kept the door shut.
You remember that first time well. Your parents had just given you both "The Talk" and you were both more then a little curious so you started experimenting. It started with light kisses before moving to heavy petting and before you knew it you were on top of your sister fucking like crazy. She moaned your name loudly as you both climaxed. That's when your parents came in and after a stern talk laid down the ground rules. Luckily for you Rabbits and Skunks are not normally able to reproduce so no condom but your parents told you that you couldn't tell ANYONE period. After you both reached the age of 11 though things became a little different. It went from just being fun to meaning something more. You started hanging out a lot more. Going out to eat together with saved up allowances. You watched movies together laying on the couch. Then it hit the both of you that you were in love with each other. This became awkward for a time as the two of you had to hide it in public. That was until the HCA. Now the two of you are regularly seen dating and making out. Some see it as weird but the two of you don't care. The HCA allows incest and also the two of you aren't even related.
You enter your sister's room without knocking. A privilege reserved for you as she is sitting on her bed in her bra and panties. The lacy ones you bought her after the HCA for your planned celebration. She looks up from her magazine and smiles. "Hey big bro. Want something?"
Remind her you two have a date planned
Lay down next to her and start making out