Movie date help!!!!!?

Ok so everyone has been telling me that this guy likes me and I like him too on friday we are going to the movies with two othr friends kinda like a double date and I was wondering what I should wear? I have this really cte purple and black cheetah print romper (strapless) that he hasn't seen so I wanted to wear that any advice? Also how should I act/flirt with him? Thanks:)