Most Helpful Guy
From a good guy perspective point of view, because:
1. There is a lack of responsibility or duty in the relationship (failure of the girl)
2. This relationship has not gone on long enough to be worthy of special treatment
3. Guy realises he was blinded by love and in an incompatible relationship
4. Guy realises the girl is a different person after uncovering her "true nature"
Yes I know this is kinda biased that the guy is not at fault, but I am just imagining a scenario where the guy is a good guy because I can relate better to that.