Nice try, though.

It was no secret that Fil's grandfather and Vincent's grandfather were great friends. Despite the differences between a simple local farmer in a remote rural town and an excellent businessman in the city, they maintained a great friendship. Even until the day her grandfather died, the chairman grieved with the family. 

In other words, Fil has known the chairman since she was a child and used to be very fond of him. After all, she would often come with her grandfather to visit the chairman. It was how she met Vincent. Her relationship with him, or rather, her view toward him, only turned sour ever since she started feeling how the chairman seemed to forget his friendship with her grandfather.

The birthday invitations were probably one of the factors. Not that she was bitter about it, but it still left a sting. But now, the chairman was telling her it was she who had never accepted his invitations.