Can two people be friends if only one is in love with the other?

I have a friend who happens to be a girl and we've been friends for a few years now....she has expressed her interest in a relationship before, but I always let her know upfront that I think of her as a good friend and have no romantic feelings for her...I really enjoy her company when we hang together and I'm careful not to do things that would indicate that my feelings has changed....

But now I have this dilema...a few days ago we went to her relatives house and when asked about our relationship, I unabashedly said that we are nothing more than friends...that night on the way home I felt as if she was trying to say she was in love with me and she seems to be convinced that I'm her husband! That really irritated me to no end because I do my best to ensure that I don't toy with her emotions by being upfront....So I stopped answering her texts...I've become very fond of our friendship and would really be saddened to loose the friendship, but I'm beginning to think that we can't be friends if her emotions continue at this level...I talk to other women and i don't want her to think that shes being cheated on when I have been very upfront and plain about how I feel....

Not sure of what to do in this instance...right now I'm irritated and sort of upset because she seems to go on thinking that we can be more than friends while I really just enjoy her company.....should the relationship be severed because she's in love and I'm not or should our contact become very limited?

btw...we've never had any romantic involvement, not even so much as holding hands..