It's sort of like, he really wants to stay true to her, and he misses her so much while he's away.
But inside, there may be a part of him that knows/ is thinking that she isn't being faithful to him, so in the end he decides that he's never going back to her.
It's sort of like, he really wants to stay true to her, and he misses her so much while he's away. But inside, there may be a part of him that knows/ is thinking that she isn't being faithful to him, so in the end he decides that he's never going back to her.