Need advice on this situation please?

I say don't worry about it. She is obviously miserable with her own life therefore has to make up lies to seem interesting and get people to listen to her. If she is a known liar in the workplace, whose to say anyone would believe her anyway. Your business is your business. If you guys wanted to make love all night long, as long as it doesn't affect your work during work hours, it shouldn't matter. Worrying is only giving her the satisfaction and attention she obviously craves. Ignore her.