Unexpected Hookup at Work Party

I've been married for twenty years now, but I'm still exploring and dating casually. Last week, we had a work holiday party where everyone was in high spirits after drinks. My coworker Lisa, who's in her late thirties, has always struck me as intriguingly flirtatious. We both ended up alone near the bar for some quiet time, and before I knew it, she pressed herself against me. Her hands were everywhere, and we kissed like there was no tomorrow right then and there. It was thrilling, and yes, a bit taboo since we see each other daily at work. After that night, I found myself checking her out constantly but also feeling guilty about my actions. Our little fling has stayed strictly under the radar so far, but it's become something I look forward to.