Not quite sure on your age but...Switch the tables on her!
Maybe it is your constant persistence that makes her think maybe you are ONLY after that..
I would joke around a bit and pretend you are the one that is being prude. When you make out guide her hands to you but stop her and tell her "maybe this is a bad idea..." give a sly smile.
Find out things that turn her on and make her desire you, these aren't always actions they could be certain keywords.
What i have done is joke around a bit with girls even if its through text saying that you aren't that type of guy that would sleep with them. The girl will usually respond with "what makes you think i want to sleep with you?" and just fire back "you wouldn't be smiling at the text if you didn't think about it at least once
".You have to make it seem like it is HER decision/action to go farther not yours.