A Girl says she doesn't like me than acts like she does?

it seems like she realized she does like you after seeing you with another girl, but I say just ask her, if she says no again then tell her she cant sit on your lap or touch your hands or flirt like she does and not expect you to think she is into you. I know for a fact (because I do it), If I kinda like a guy but not too much I will act this way to keep him in my reach if i realize I do like him. I know I shouldn't do it its a B*c*h move but yea I hate being lead on but I kinda do it too. but really ask her and if not then just tell her, its the only way she will stop if she really isn't into you that way.