Should've known better

I was divorced and living alone, no children and no alimony payments. I worked later than usual and was heading home, walking as usual and I came upon my single neighbor very drunk also heading home. I helped her to her apartment, and she invited me in for a seasonal drink. It was Christmas eve 2021 and I accepted and had a drink than another and we slept together. Christmas morning, I got home and put it down to good luck. Anyway, as a 35-year-old I thought it was great fucking a 28-year-old woman. Good looking as well, but as the title says I should've known better. She was a quiet woman the whole time I've known her, and I hadn't seen her go partying or on any dates either. She kept to herself and had been to a work party and had too much to drink and had headed home before it took full effect. I met her on her way home and by the I got her to her place she was totally changed by the alcohol. So, we ended up fucking and she of course got pregnant. Short version we married as it was the easiest way to solve the problem of her being pregnant and neither willing to get the baby aborted. We've had a son and for the most part we're happy. It took some getting to know you moments, we bought a house together and are getting on better than I thought we would.