Friend that is hitting on me?

Ok one of my new co-workers and i have been getting along good. I am happily engaged to the man that i love. I am at a new job and this girl is the only person i really know. She has openly admitted she likes to fool around on her bf with other women. This shocked me to my suprise i took it at face value and just shook my head well we have done the whole girlfriends thing like shopping and hanging out have dinner parties. Until the other day i had fallen down off the counter and hurt my back while changing a light bulb. So she just all of a sudden starting giving me a back rub. That didnt bother me until she told me of stuff she would like to do with me. I just kind of shrugged it off until today while at my desk i got a dirty email and asking me if i wanted to come over tonight. How do i say i am not like that but i dont want to lose a friend. My fiance laughs and thinks its funny but i dont how do i say stop hitting on me without being mean?
Friend that is hitting on me?
you have to explain to ur friend that u r not gay and tell her that it makes u feel unconfortable if she doesn't respect that u might have to lose a friend i no that u don't want to do that but if theres no respect theres no friendship
Friend that is hitting on me?
Tell her you're not interested and happily married to someone you love and wish not to hurt his feelings. Also tell her she is making you uncomfortable but you (if you personally want to, not your friends) can still be friends.