Late Night Shift and an Unexpected Encounter

I've been with my partner, Alex, for over three years now. We're both pretty grounded in reality, but one night after closing at the cafe, I found myself overwhelmed by a sudden urge that felt out of character, something primal and needy bubbling up inside me as I closed down alone, every inch of skin tingling with an acute desire for attention and touch. As if sensing my state, a regular customer who's always flirted a bit came in late, looking more aware than usual, his eyes never leaving mine. We've talked about boundaries plenty, but in that moment, the electricity between us felt too strong to ignore. Before I knew it, we were pressed against the fridge, fingers slipping under fabric, breaths mingling in a way that was both shocking and exhilaratingly real. I don't know how much time passed before reality clicked back into place, Alex's number flashed through my mind, along with thoughts of home. The rawness of it all left me feeling shaken but also strangely relieved. I'm still trying to process everything that happened, unsure if it was a momentary lapse or something deeper stirring beneath the surface of our relationship. Does anyone have any insights on what might trigger such intense desires out of nowhere? Is this normal for people in committed relationships to suddenly feel this kind of pull towards someone else?