Some people think Marian is not really dead.
I'm like NO. Damn it NO. I hate love triangles.

I can't see them in a triangle with anyone else, because they would clearly always pick each other. This is not a situation like Neal/Emma/Hook, OQ are already attracted to each other and they are soulmates. When Regina loves, she loves deeply and she's extremely loyal, i can't see her with anyone else.