Yeah I remember this old amateurporn clip of a tall blonde muscular Chad and his 5'2 sister with a perfect little body (note: Im not just making stuff up, I actually seen this clip). They were both adults in their 20s during the shooting, but she said they started fucking since age 12
They lived in some hicktown and shared their story about how they never thought it wrong to have sex. And the way they fucked showed how familiar they were with eachothers body too.
The sister just loved her personal fucktoy who would always give her what she needed (the action was always focused on her getting off, he performed more like a workhorse/mule with big dick than a dominant "need to cum asap" kinda guy.
She was definately the smart one in this dynamic, getting her little pussy pounded since young age and never having to face judgement from the outside world (because: small hicktown in the early 90s)
It would be different nowadays, keeping it hidden especially if you live in a larger city/nosy town. @Karlicel if I ever find that clip somewhere I will def dm you.