My Non-Monogamous Dilemma

I'm in my early 30s and have been in an open relationship with my partner of five years, Alex. From the start, we agreed that while we would be committed to each other, we would also maintain our own individual sexual freedoms. The arrangement has generally worked well for both of us, but lately I've found myself increasingly attracted to someone outside our agreement. Sarah is a colleague at work and she's in her late 20s. We've clicked over similar interests and shared humor, which led to an undeniable physical attraction between us. One night after drinks with friends, we ended up back at my place. The moment we stepped inside, the tension was palpable. I told Sarah about my relationship status beforehand, so she knew what to expect. Despite this, our chemistry was overwhelming. We started kissing, and I felt her hands exploring my body as mine roamed over hers. She pushed me onto the bed, straddling me with a hungry look in her eyes. Her breasts were soft against my chest as she kissed down my neck and collarbone. My fingers delved into her hair, pulling her closer to deepen our kiss further. Her arousal was evident when I touched between her legs; already wet for me. We barely paused before removing clothes hastily and continuing the intense foreplay. When we finally entered each other, it felt like an explosion of sensations. She moved on top of me slowly at first, then picked up a relentless pace that left both of us breathless and gasping with pleasure. Her body was slick with sweat as she rode me harder, her moans filling the room. We spent hours exploring each other's bodies, trying different positions, teasing and pleasuring each other thoroughly. Afterward, we lay tangled together in post-orgasmic bliss, talking softly about our feelings and what this meant for us moving forward. My question is: Is it normal to feel such intense attraction towards someone else while being committed? How do you handle these feelings within a non-monogamous framework without hurting anyone involved? It's left me questioning everything.