A Mistake in the Break Room

I just ended a long-term relationship and thought I was over it all. But last night, after work, I found myself alone with a coworker in the break room. We had flirted before but never acted on it. I told her about my breakup, she listened, then suddenly we were kissing like there was no tomorrow. Before I knew it, I was undoing her pants and guiding her onto me, our bodies pressing together as I thrust into her with a desperate urgency. The sensation of being so close to the edge, feeling her tighten around me... It was exhilarating but also made me feel guilty for using someone right after my breakup. We pulled away eventually, both breathless and confused, looking at each other like we had just committed some kind of workplace felony. I left then, knowing it wasn't fair to either of us, but the physical memory haunts me.