Dora is wrong for, as paladin_revenant said, assuming that Faye was trying to hurt Marten. She's also wrong for invalidating Marten's feelings on the matter. Marten's not upset, and she's telling him he's wrong for that. Then she's wrong for mocking Marten, though she has some provocation to work with there, since Marten was sarcastic about her feelings.
Marten is wrong for responding sarcastically to Dora's reaction, and for invalidating her feelings. He has some provocation from the start, since Dora's being irrationally nasty towards a friend of theirs.
Steve's thing bugs me. We've descended into the trope where men are always wrong in relationship conflicts. Marten comes down from his anger, not into a space where he can consider things calmly, but a panic state where he realizes he forgot about
the rules
.
Specifically:
#5: The female is never wrong.
#6: If the female is wrong, it is due to a misunderstanding which was a result of something the male did or said wrong.
#7: The male must apologize immediately for causing said misunderstanding.
#11: The male must remain calm at all times unless the female wants him to be angry or upset.
Not that I believe that women actually always behave this way in reality, or would seriously advocate these positions, but they represent stereotypical behaviors that are often used for comedic effect in pop-fiction. I'm a little disappointed in Marten's lack of spine. He's gone into abject apology "are... are you still mad at me?" mode about a situation not of his making, where the ultimate resolution has to come from Dora getting over her issue with Faye, not Marten making things right by prostrating himself.