From what he told, he was Emma’s first crush.
Last Harry Potter movie was done almost more than 8 years ago, but most of the actors are still in the same circles.
Other than Harry, most favorite characters were played by Emma Watson and Tom Felton, even though they were not really friends within the movie, they have spent quite some time together.
7 years ago Emma herself admitted that Tom was her first big love. In several interviews since then, she has mentioned that for at least first two movies, she had a big crush on Tom Felton and that she was her very first crush. She even has mentioned that he knew about it at the time.
But recently Tom Felton in several interviews have mentioned that these feeling weren’t mutual. He tried to get away from these questions with a firm “No”.
But he admitted that during the shoot of second Harry Potter he kind of recognized that she is in love with him. But during that time they were recording the famous scene, where Emma slaps him across the face and at the time he and his ego did not know how to react and that kind of ended the possibility of their relationship.