I love that line. Also, 'try not to die, I would miss you if you were gone.'
You just really get the sense that Dorian doesn't have a lot of friends, and the relationship with a friendInquisitor, whether romantic or not, is very important to him. It was one of the better friendship paths bioware has done. I really felt attached to Dorian. I like to think he and my Lavellan have sort of a brother/sister relationship.
This is actually the first game where I would say that my player character's closest relationship isn't with his/her romantic partner. Morrigan and my Warden got along fabulously. Garrus and Shepard were pretty much inseparable from the start. Solas and Lavellan are certainly in love, and they do care for each other, but there's also a wall there.
Which isn't necessarily a bad thing either. It was part of what made the romance feel very different from the rest.