No one wants to get down and dirty all the time. Well...men KINDA do. But we're genetically predisposed to this behavior.
This doesn't mean your lady friend doesn't wanna get down too. She just doesn't want you to let any dumb stuff get in the way like your XBox, poor hygiene, or general stupidity. The sad part is she loves you so much she don't wanna tell you what she really thinks.
Or maybe she HAS told you and you just didn't listen. Consider this as reinforcement. Take notes and get better you dummy.