Tears of joy or of sadness?

The other day in class while watching the Godfather the scene were Micheal tells his recovering father, "Im with you now...Im with you", obviously meaning before that he wasn't "with" him. When Don Corleone hears this tears come to his face, although he has a smile on his face it contradicts what he has said before to micheal: telling him he doesnt want him to be part of the family business. Obvioulsy he was lyinh and because of the smile on his face it tells us that he is proud of mivheal and that he is shedding tears of joy.

-Seabas