Board Thread:Character Discussion/@comment-10062920-20141013031913/@comment-10062920-20141013035217

Unlike David who was hiding what he was doing with Mary Margaret, Robin is very honests to his wife about everything that was going on and his feelings. We don't know that he isn't unhappy with Marian or that she's unhappy either.

On top of that, I can bet that Robin still loves Marian truly. He cares for her to the extreme and that too can be a form of true love, not just between 2 "lovers" chosen by the demographics of the tumblr-shipping community.