Questions: Dating

I had this happen a few moths ago. I had 4-5 prior conservations with this young woman. She never mentioned being in a relationship at any point (I was listening carefully for that). I very cautious with her because I didn’t know her age but I was guessing she was in her mid 20s and I was 40 at the time

I finally gathered up my courage and asked her one day if “she would like to get breakfast”. She smiled and said “thank you but I have boyfriend”. I apologized and said I didn’t know and said I wouldn’t ask again. I was disappointed but also relieved that she smiled because the last thing I wanted to come off as was an “old creep”.

But later I came to believe she was lying. I guess I get why. It’s the best way to spare a man’s feelings and also prevent him from keeping trying. But I really don’t like being lied to. Rather her say “thank you Joey but tbh I am just not interested in you that way.”