What killermunkyz said. I used that method a week or 2 ago and it worked a treat (ended up not going because I had a better option) but it's very good.
I will say though that in the build up to me saying that 'line' I began by saying that I was thinking of watching a movie but couldn't decide if it was too late or not (it was 3am, clearly too late) I then said something about having to watch it with my sister 'tomorrow' if I watched it then and that she is the worst person to watch movies with, but I put at the end of that sentence "(besides you of course

)" this was my little bait, which she bit on asking why she'd be bad to watch a movie with, I said I just had a guy feeling and she should convince me otherwise, she qualifies herself saying she gives great cuddles during movies, I said "that's good enough reason for me, ok i'll bring the movie and the popcorn, you provide the theatre!"
I don't think you'd have to do everything I did but it seemed a more natural progression into the end statement.