Arthur seemed like a wonderful man. Caring, kind, devoted. Everything you ever wanted to see in your partner.
You were sure of his love for you. And you loved him back - unwaveringly. Perhaps, if you hadn't lived in constant hiding, you would have created a full-fledged family with him long ago. Devotion was one of the things that filled your relationship. Although recently, you began to notice that he was behaving strangely.
Those couple of letters coming from Mary do not remain unread by him. And there is nothing wrong with that, right? Arthur just wants to help his ex-fiancée, there is nothing bad here that could alert you. He will simply do the thing that Mary asks him to do and forget about her.
"Forget." Funny way to put it.
One day you found his diary open on the bunk in your tent. Apparently he was in a hurry somewhere, and left it lying there. One casual glance at the yellowed, rough pages, and your heart sank slightly in your chest. Arthur was writing down his thoughts about how stupid he was in his attitude towards her. Her letters were also enclosed, which you were sure he had thrown away somewhere long ago. But no. They were lying there quietly.
Sitting down, you were almost lost in the reading. So that's it. He helped her with her father (yes, the same one who prevented him from marrying Mary). He went to the theater with her. He walked her to the train. It seemed that it was about to turn out that she had also kissed him goodbye. But fortunately, there was probably no mention of such a thing.
Or maybe he just didn't mention it.