Except those social skills classes kind of do not apply to the woman who gave birth to you and raised you from childhood, and applied to her they are pretty passive-aggressive. I guess if you have a really bad family situation that shit applies? Maybe? I don't want to fucking go into that. Marten, the person who matters here, has a mother who loves him and who walking off on would be shitty and childish.
It's also, to me, pretty clear Veronica was doing it to get a reaction and make him stop stewing in his own BLUH BLUH, which is what he wants to do.
If anything, Marten's reaction here is a good one--he goes "Mooooommm, GOD", and she goes "oh shhhh" and that is how things work because she's his mother.
If it was one of his friends doing this? Sure, walk away! But it's his mom.