I really agree with AquilaIncerta and TheeAbecedarian... he's just trying to justify tweo things: his hurting her, and his getting hurt. Like he says that he told her he could lie, he's a guy, etc., so he's saying these things as if he's telling her "you were forewarned," but he's more than likely he's telling them moreso to himself, as if he's saying "We knew this would happen, and it did" but both of them were too happy or too scared to stop it.
I really agree with AquilaIncerta and TheeAbecedarian... he's just trying to justify tweo things: his hurting her, and his getting hurt. Like he says that he told her he could lie, he's a guy, etc., so he's saying these things as if he's telling her "you were forewarned," but he's more than likely he's telling them moreso to himself, as if he's saying "We knew this would happen, and it did" but both of them were too happy or too scared to stop it.