[Part one of a continuing series as my pregnancy progresses! 1st trimester, 3 months pregnant, little bump, real pregnancy test] [[[TLDR; your pregnant sister needs help hiding her pregnancy from your parents.. so you agree to help her, as long as you get to fulfil your pregnancy fetish fantasies with her at each stage of her pregnancy]]] Long description: You're sitting on your little sister's bed when she comes out of the bathroom holding something.. as soon as she sees you, she hides it behind her back. She looks worried and agitated. You ask her what she's hiding but she is hesitant to tell you at first. She soon buckles and tells you that she has been carrying on seeing the boy that Mom and Dad told her not to.. and even worse she's been letting him fuck her raw. Now she's pregnant.. and she doesn't know what to do. Mom and Dad will freak if they find out! She begs you for help, you'll be the best big brother ever. She wants your help concealing the pregnancy and keeping Mom and Dad clueless until it's too late for them to anything. Being the kind and amazing brother you are, you agree to help her keep the pregnancy a secret. She looks so relieved and thanks you. She thinks she's around 3 months pregnant and is already starting to show a little bit.. none of her clothes fit her properly any more. You suggest that she puts on something a little more baggy than her current outfit.. she agrees that it's a good idea. She stands awkwardly, waiting for you to leave the room... but you tell her that you'd like to watch to see how much of a bump she's showing. Considering as you agreed to help her, she lets you stay. She takes her clothes off and you see her stomach is already starting to poke out. She has a tiny little bump and her breasts are looking swollen. Something about seeing your little sisters pregnant body makes you aroused and you can't help but tell her how beautiful she looks. She looks bashful and confused. She likes hearing you say it, but knows it's wrong coming from her big brother. You gesture her towards you and start to caress her large, round tits. She lets out a little moan of pleasure.. then quickly backs away. She's not sure you should be doing that. You remind her how much of a big favour you are doing for her by keeping her secret.. and she agrees to let you, just this once. She takes off her panties and notices your hard cock through your trousers. She's flattered that you find her so attractive.. and it's starting to turn her on too. She lies on the bed for you, showing off her little bump. She can't believe how much you like her pregnant belly. You're so horny by watching her naked that you can't take it anymore and need to have your cock inside of her. She is worried at first, but soon you are pushing yourself inside of her pregnant pussy and she loves it. Her pussy is so sensitive and wet.. and it's so wrong that you're fucking your pregnant little sister whilst your parents are downstairs.. but you both can't help yourselves. After feeling how good your cock is inside of her, she agrees to let you fuck her throughout her whole pregnancy.. as long as you keep her secret. Imagine how much bigger her belly will be with every month goes by. You get full access to her growing pregnant body. You don't have to worry about protection as she's already pregnant, so you can dump your cum inside of her too. You release your spunk inside of her and can't wait for the next time she comes in for your help.