Marten, on the other hand, never seemed actively invested in their relationship.
Error.Marten was definitely invested in the relationship he thought they had. Marten doesn't do what I or you might do in a committed relationship, but always seemed willing to do what it would take, as long as he knew what it was. It was not like he knew that Dora had such an issue with the Faye dynamic. It wasn't like Dora ever asked him to change his situation, and we can't assume he stressed enough about the relationship for it to occur to him that he should without Dora's input. Sometimes one doesn't know what one's relationship actually is; sometimes one doesn't know who it really is one has a relationship with.
Ignorance or idealism isn't the relationship killer...refusing to communicate and try to rectify inevitable differences is.
But you're right, in that Miss Reed will in all likelihood not antagonize Dora. Probably won't even go to see her (though they might bump into each other for dramatic/comedic effect).
Dora made some bad decisions regarding the relationship (which is functionally different from making
no decisions ala Marten), and basically ruined the chances of fixing/making it stronger with unearned mistrust that she didn't actually attempt to get over (by, for instance, communicating with Marten or
anyone about her needs/fears/whatnot). But that is her privilege and wont as part of a two-person partnership, especially if Marten's life is stalled so much that he doesn't initiate much in the relationship.
Veronica said that she thinks of Marten as a grown man, and she was perfectly nice to Faye except for the one threat (that was obviously half or more facetious). The most she could possibly take issue with are Dora's actual actions when she was jealous/paranoid, or specifically only the porn-search (since the others were ameliorated). Which very few people would think matters that much.
But Dora still needs a reality-check. Not necessarily a harsh one, but Veronica's would be funny.