The first thing I would do is spank and grab that ass with both hands and let her feel the tight grip of each finger sliding across that big ass booty while slowly loosening that grip as I spread those cheeks wider to make room for my dick.
Then I would gently place it in between those cheeks and let it rest on top of the booty hole as I slowly let go of each cheek so that my dick gets buried in between.
Lastly, I would press both cheeks from the outer side and I fuck that warm and oily ass crack until I bust a huge ass load on her shiny ass and let her mesmerise me with sight of my jizz dripping down her cheeks as she twerks and makes slutty ass noises. Fuck!