Marten and Raven? Mmmmh, while I suppose it's not totally implausible, somehow I find it doesn't... resonate, so to say. Let me explore the idea.
We've never seen Raven manifest this kind of interest towards Marten - although it could have been out of self-preservation, with Dora and Faye around.
She helped Dora make her move at Marten.
She never seemed to have any interest in commitment, but she may have evolved on that respect.
Marten confessed having sometimes fantasized about Raven, but it's not quite constitutive of an significant attraction.
Other than that, he didn't show any special interest to her.
Then again, at the time, he was with Dora, and before that he was in a
position that... didn't need to get
more complicated than it already was.
Ultimately, it's just their respective characters: I don't find they spark. I see nothing coming between those two.
At least romantically.
On purely carnal standpoint, I can see more of something.
Raven is not known to be shy about these matters, in
a pretty open and non-devious way - the latter point making it possible for her to have second thoughts, out of her friendship with Dora, even if she was interested.
Marten, as mentioned above, has fantasized about Raven in the past, but he doesn't seem to feel comfortable with casual sex. How he would react if she threw herself at him is an interesting matter for speculation.
Still, really, I don't really see them as any kind of item, although I admit it's not impossible. And hey,
it's just me.