Er, that sort of thing is considered to be extremely bad fandom ettiquette. You're essentially going up to someone and saying, "Hi! These are all my sexual fantasies about you with another person, and I'm going to shove them in your face!" There was a huge kerfluffle about a year ago in LOTRPS when some twit came up to Ian McKellan and his SO while they were eating and babbled on about RPS and gave them her website address. It's basically the height of rudeness, to both the actor and to the fellow fans.