<human>: Can you provide a brief overview of the text?

I started dating a girl from one of the big online apps about a month ago. We went on a few dates and since everything seemed to be going well, I decided to introduce her to my friends at a booze cruise (traveling around the city harbor in a yacht) birthday for a friend. When we arrived I realized that there were a lot more people than I was expecting, most of whom were acquaintances. I introduced her to my main group of friends who were in a circle, and entertained the occasional handshake from acquaintances who did not join our circle. 

She had fun at the party, but later confided that I had hurt her feelings by not introducing her to everyone I talked to. I was unprepared for this response, and my immediate reaction was rationalize, explain my intention, and otherwise gloss over her feelings. We got into a fight about my reaction, and later she decided that she couldnt trust me with her feelings and emotions which led to a decision to stop dating. 

The thing is, I realize this has always been how I responded when a partner has said I hurt their feelings. I usually try to explain that my intentions were good and that it was a missed signal or something I innocently overlooked, however that never gets me anywhere. What is the appropriate response when a partner says their feelings are hurt, and why do I feel the need to rationalize and try to get myself off the hook? How can I improve myself in this area?
<bot>: Introduced date to some but not all people at a party, learned I hurt her feelings, struggle with how to respond to hurt feelings.