An enemy attack on your feelers:
lol 
Well, you see, for me the problem with Cullen starting a relationship with somebody else is that I only have 2 variations of Thedas. In one of them Cullen is with my Amell, and they even have a kid, and I spent years of my life on that story, and it's kind of a canon for me. The other is the AU where one thing happened differently, and my girl didn't end up in the Circle, and she didn't meet Cullen, and she wasn't recruited by Duncan, but there she becomes the Inquisitor instead. And meets Cullen. It's fate! So if I create a second Inquisitor with my Amell import, I'll be headcanoning that he continues his relationship with my Amell somewhere in backround, and she hangs around, maybe doing some scouting for the Inquisition, because she's a sneaky shapeshifter, and she's good at stalking enemy forces, and their kid is squiring somewhere in Skyhold, and Cullen is totally loved, and they are basically a family. So if instead Cullen will start going out with another NPC, it will blow a huge hole in my ship, so I hope he won't. At least if it's Amell/Surana import. I know some DAO fans who want the same thing - Cullen to reunite with the Warden, because we've been shipping it forever, since before anyone knew Cullen would be back, and we thought devs would never do anything with him, and he was safe to grab 
I know it's probably a silly reason to object, but it's important for me. So I'm hoping Cullen won't be actively looking for love, and maybe even the Inquisitor will have to work hard to get him 