Can a man fall in love with a woman he thinks is only a one night stand?

Hey men in particular!! Did this ever happen to you? Where you went out with a woman (say even a friend) one night and slept (or made out pretty heavy without full sex) with her thinking it was all just casual and that. Then you realised later on, some time after that you had fallen for her? I'd love to hear any stories from you guys please.|||No it hasn't happened to me cuz I only know girls who don't get sex yet so that's why.