is she older or younger sister of yours?
how old are you two?
maybe it's just your hormone are still developing your body and it affects the desire you have~
maybe you think it's okay if you do it once or twice...
but... for me... sex is just like drugs~
you can't stop it just by doing it once~
it makes you crave for more...
so~ please consider it if you are out of control and accidentaly have an impaired child because of it...
it's okay if you're not blood related... but... are you sure?
i find it my older sister is also attractive to me...
thou i know that she's not vorgin anymore...
we also sometimes sleeps together(without doing anything... it's just because our parents are using my sister's bedroom... our parent's room are a little bit far from our main house...)
but everytime i can't hold my lust, i would go to toilet in the middle of night and just go fag myself out...
done~ then i'll just go to sleep beside my sister...
hahahahahaha!!!
sometimes faging is wiser choise than just go with your desire...