I don't think this guy was that kind of predatory person (although perhaps my father's first wife was. it's entirely possible that she only married my father for her green card but misled him into thinking she was really in love with him in order to get it. ) The letters from the lover make it clear he's really besotted with her and would like for her to leave my father and marry him. She may just have been someone who wanted to have her cake and eat it too. Maybe she led the lover on making him think she might leave my father when she had no intention of doing so. Maybe she just needed to stay longer with my father until she got her citizenship (I have no idea how it worked in the 1940's, I think today you have to be married at least five years and any breakup in the relationship sooner than that would trigger suspicions that it was a fake marriage.)