A Night Shift's Secret Fantasy Realized

I work night shift at a warehouse. The days are long and lonely, with just my thoughts for company until the early morning light signals when I can go home to Alex, who doesn't know about this side of me. He thinks I'm straight-laced and boring. Little does he know that the darkness breeds my fantasies, one night stands in particular. One evening, while on a rare break during a quiet shift, I was scrolling through an app meant for adult roleplay. Suddenly, there she was, a beautiful woman named Ruby, looking for someone to fulfill her desires. She asked if I wanted to engage in what I thought of as taboo play, but it felt like the universe had brought us together. We exchanged messages and made plans to meet up that night after my shift ended. The anticipation built all evening long. When we finally met, her confidence was magnetic, commanding attention from every direction. She led me to a motel room where everything would unfold under the cover of darkness and anonymity. I took off my clothes first, feeling exposed yet excited. Ruby had an air about her that made my heart race as I watched her undress slowly, teasingly. Our bodies touched for the first time, soft skin brushing against mine, a sensation I hadn't experienced in years with Alex. Her lips were gentle but demanding as she kissed me deeply. She guided us onto the bed where we explored each other's bodies thoroughly. Every touch was deliberate, awakening parts of me long dormant. We started slow, letting pleasure build between us until it couldn't be contained anymore. I could feel her hands moving over my skin in a way that sent shivers down my spine. Ruby positioned herself above me and began to move with purposeful grace. The rhythm was intoxicating; every thrust brought us closer together, our breaths mingling as we lost ourselves in the moment. Sweat slicked our bodies as the tempo picked up. I felt myself pushing back against her, matching her intensity. After what seemed like an eternity of raw sensation and unfiltered desire, we climaxed together, a shared release that left us both trembling from head to toe. Lying there afterward, still entwined with Ruby's arms around me, I wondered if this was truly my fantasy or just the escape of the night shift. When morning came, so did reality: back to the warehouse and back to Alex. Yet, part of me couldn't forget what had transpired under that dim motel light. The encounter stirred something inside me that's hard to explain. Is it wrong to feel this way? Have I betrayed Alex or merely satisfied a deep-seated need? What do you think, am I the asshole here?