often when my ex boyfriend wanted to engage sexually with me i would try to show i dont want to do it, but he would continue anyway, i doubt he was doing that on purpose, and i felt bad with outright saying no to him if he didnt realise when for example i was moving my hand away etc. i kinda feel like its my fault that i felt used by him but at the same time i think if your gf moves away you should do some thinking and just let her stop