Merely curious, was the working relationship between the two of you already strained/tense? Said another way, were you already planning to depart from the company before the senior programmer asked you out?
I have a certificate in GIS. In the 5+ years at that company, he was the only person who knew what GIS was without me having to explain it. It never crossed his mind that I might have IT ambitions or that my technical training might have value for the company. He just saw an attractive woman, and that was it. This helped convince me that the company was simply not fertile ground for a serious career for me.
My department was a pink collar ghetto. I had no desire to remain in an underpaid pink collar job and use the company as a means to marry well. He no doubt made at least 3 to 5 times what I made.