DOCP-217 "Tip up to 3cm!" Me and my cute little sister's almost incestuous sex life

I was finally able to have sex with my sister, but I decided on my own rule: ``Even if I insert it up to 3cm from the tip, it doesn't count as sex.'' - However, it feels so much better to put just the tip of the dick in and out of her pussy, and my sister gets excited as she gradually wants to insert it deeper and deeper! - Insert it all the way! - ? - What's more, even creampie...!