When I want to watch a movie with a girl, in my room, in my bed, I just lead her there. Either something like "come on, we're watching it in here" or perhaps I don't say anything at all. There's a nicer TV in the living room with a very comfortable couch. Once, I didn't even have the TV in my room anymore, just brought the laptop in and then set it up in a way so we could spoon. Though, now I just like to make things happen on said comfy couch.
Point being, you don't need a good reason, you don't even need one at all. Ideally the reason is because you two are dying to rip each other clothes off. The important thing is to establish compliance and have her comfortable with you leading. And of course, all of this is necessary in the PU as a whole!
Hope this sparks your fire, baby!
-JJ