Well I found the answer to my own question! In case anyone else wonders what Dorian says to you while romances in What Pride Has Wrought:
Oh and I remember seeing it discussed already but I can't remember what pages. I'm really sad about Dorian leaving for Tevinter. That conversation sucked. Ultimately I did what I thought was the right thing for my character to say he understood if Dorian needed to leave. But it's so sad! I'm sure they stay in a relationship, and I imagine them writing letters & lengthy visits. I just couldn't stop him from doing what he thought was right. What did you say to him in that convo, and did he stay or go?
Yeah I also tend to tell him to go if he has to, but after reading some other opinions on why they tell him to stay and my being far more aware of his disapproval in my current play through (I honestly think maybe one or two more disapprovals will do me in lol), I feel more inclined to emotionally blackmail him to stay...if I even get the chance. Dorian is just a bit too compassionate for reforming Tevinter, I just see him getting himself killed. 
I had just finished the "Under her skin" mission and I got a disapproval from Dorian for
to get further info out of him. He also disapproved in my last play through when I
for info. Dorian wanted to honor his wish. I think my decision was for the better because any info he had could be useful to our cause. I would imagine that in Tevinter Dorian will see all sorts of terrible things as he fights for reform, but his unwillingness to make the unethically tougher choices could doom him. Not that doing the opposite of my choice is a bad thing but that in Tevinter I'm sure he'll come across a lot of unethical magic use and he may have to resort to it himself to get any sort of edge and he just seems unwilling to do so, which is understandable, but not for Tevinter.
He also has a bad habit of wanting to do things on his own with no help and I don't think that is going to equal success in the long run. He refuses the help of a powerful ally (The Inquisitor) because he thinks he needs to prove himself as being more than just the Inquisitor's lover but he doesn't realize that the Inquisitor didn't get where he is without aid. I wish my Quizzy could have told Dorian that when he turned him down.
@Joe, I currently have Dorian wearing Royale Sea Silk w/ Blue Brocade. He looks so darn good. 