Letting My New Pervert Stepbro Use Me

I (Danny Cash) find myself entranced by her. My step-sister, Kira Perez, exudes sensuality. She moves provocatively in the shower, the suds cascading down her figure.
Upon catching me gazing, she appears displeased. Another time, she dresses in skimpy clothing while listening to music. As she stretches and lounges on the bed, I almost catch a glimpse of her private area.
Once again, she catches me staring, her reaction less than pleased. She eventually initiates a conversation about it. I confess to admiring her rear end.
Although she finds it odd, she handles the situation graciously. She allows me to watch as I pleasure myself, forbidding only physical contact. Before I can conclude, we are interrupted.
Days later, I make another attempt. I request her assistance in masturbating, to which she obliges by providing manual pleasure. She inquires about my sexual experience.
Admitting my inexperience, she proposes intercourse. I eagerly accept. She nonchalantly browses her phone as I engage from behind.
Eventually, she allows me to switch positions, penetrating her vagina. Despite her efforts to conceal it, I sense her enjoyment. I thrust vigorously until climax, releasing onto her backside.
Could this be the beginning of a mutually beneficial arrangement?.