A couple of dirty ideas I've been toying with

If you're interested in any of these shoot me a message, everything is up for debate and can be changed/tweaked/modified.

Idea 1: "Uhhhh I think your love for your brother is starting to show."  

"YC is a woman who has dedicated her life to her little brother, after the death of their parents she was left as an 18 year old to raise a toddler all on her own. Over the years she sacrificed a lot, giving up college, working multiple jobs, scratching and clawing to make ends meet while insuring her beloved little brother had everything he needed. She handled all of his firsts, taught him to ride a bike, drive, shave, made sure he always did his homework and ate well, and it's paid off. At the age of 18 himself he's grown into a fine young man, graduating at the top of his class from high school and about start college with a full scholarship. However, she's found that there is perhaps one area where she hasn't prepared him yet. Being the good lad she raised him to be, MC has never had time for a girlfriend. He focused on his studies to insure YC didn't have to worry, cleaned and cooked to take some of the pressure off of her, and because of that he simply never had time for dating. But now that he'll finally have time for such things, he's a bit behind his peers on that front. It looks like Big Sis is gonna have to teach him one more thing, though he may need A LOT of lessons."

It's a simple idea, YC is more or less playing a gentle dommy mommy type starting an incestuous relationship with her little brother under the guise of it being "educational". He'll need plenty of love and reassurance but it won't be long before he's taking the reins all on his own.

Idea 2: "What's the matter, did your Futa sister steal another girlfriend?"

"YC is a young woman trying her best in life, she lives with her family while taking college classes locally and just trying to get by. The main problem in her life is her sister, MC. You see, YC has been exploring her sexuality for some time now, yet every time she brings home a new girl....MC is there to steal her. The perky futa is upbeat, friendly, and rather aggressive sexually, pair that with the natural allure futas seem to have and very few girls can resist it. One day YC has enough and decides to take matters into her own hand, finally confronting her sister and demanding she stop stealing all of her partners. She expects the worse, maybe a beating and some taunting from MC, but she never expects MC to start crying and breaking down. You see, she hasn't been stealing YC's girlfriends to hurt her, she's been doing it out of....jealousy. She's lusted after YC for years and can't stand the thought of other girls enjoying her body."

Once again a pretty simple idea, pretty self-explanatory as well so I won't go into too much else.