Dan, I'm not sure if this is the case or not, but well it's always good to NOT get between the sheets, no matter the gender. If this happened, then you've muddied the waters and she thinks you two are a couple.
Ask her to leave immediately and if she doesn't, call the police before she starts getting her mail there!!! Oh, and if you DID happen to get up close and personal, don't do it again. NOt saying you did, just saying it happens and then things can go downhill.