You know how sometimes a guy might trip then accidentally feel a girl's chest up? Well, if she says "Are you going to finish what you started?", is that more likely an invitation to continue or sarcasm? If it is the latter, then apologize and get out of that situation. If it is the former, provided she is of sound mind when making such a declaration that is done out of free will, your choice on whether or not you take her up on her "offer".