If they met in a different way but with the same personalities and characteristics, they would be the same person. If a cruel person who doesn't care about love meets an emotional person, he will fall in love with him.
So his sweet girlfriend did as those who weren't stars always did. She bandaged up her heart as best as possible, offered a wry smile, and gave him up.
Because he didn't love the girlfriend. He loved the new girl.
And the new girl had the makings of a star.
And stars, it seems, always get the happy ending.