How did she know

I had a short relationship with this beautiful Nigerian cis woman. The first time having sex with her was definitely a role reversal for me. We went out to dinner and had some drinks, night was going great for both of us so we continued drinking at my place. Kissing her was always so great as her tongue was so wet and knew just how to sensually move. She pushed me back on the sofa and pulled down my pants and began sucking my mostly soft cock, but it quickly stiffened up. She then began licking my balls and on down to my ass. Her wet tongue licking around my hole created so much juices that were just pooring from my hard cock as she began slowly caressing my balls and cock. She can tell I really liked what she doing as she then pushed her tongue into my hole and tongue fucked me for some time. She then took her clothes off and sat on my cock reverse cowgirl style. She went up and down so fast on my cock, using one hand to rub her clit and the other began fucking my ass with her middle finger. It didn't take her long to cum and as she was she kept shouting out "I'm cumming, I'm cumming...." so many times that I was actually impressed how long she continued to cum. After that she got up and used all her juices to get her ass all wet, stroked my cock a little and slide it into her tight ass, this time facing me and we began kissing as she slowly road my cock. As we continued kissing she could tell I was getting close and told me "cum in my ass, I want to feel your hot cum inside me and feel it drip out on you... just then, I began cumming, as she knew just the amount of speed to go to keep me cumming for a long time too. At first I felt that it shot a couple times out but as she went slower, cum just oozed out into her ass and I even began feeling it dripping out of her. After that she lifted up, spun around putting her ass near my face so I can smell what our cum smelt like together. She began sucking my cock, licking up all my cum and hers that was on my cock and balls. She said, in a moaning voice, "this tastes amazing, you should try this" and shoved her ass into my face. She was right, it tasted amazing, so much so that I kept hard and she began stroking my cock really fast while licking my tip until I shot another load in her mouth and around her lips. She quickly got up and shoved her cum squirted mouth into mine as we kissed until we both cleaned all the cum off each other. She then told me that I was a good little fuck boy and next time she'll let me lead.