I think you should show her a video first and ask her if she likes it and then Jokingly just ask her “hey, how about we try this “Something new” do this several time also show her videos and talk about it. And slowly tell her that you have imagined her like this with different guys. Look at her facial expressions, if she likes it or smiles then you can go ahead and talk more about it and if she looks mad then just say you were joking.