At uni, I had an English prof who seemed to have developed a crush on me. I didn't want anything to happen between us as I wasn't particularly attracted to him but I enjoyed the tension between us. We'd sometimes meet at the student cafe before class or stay a bit after class and just chat.
After I was done taking both of his classes, he invited me over for dinner at his home. His wife had cooked an elaborate dinner, which I felt bad about as I forgot to mention that I am vegetarian. He'd told me that they'd met because they were both fighting over the same person but it's only later that it dawned on me that there was more to the invite than just dinner.