a guide line to instructors and teaching assistants says:
"It is not appropriate to date or flirt with your students. If a student is flirting with you, make it clear that you are not interested and that this behaviour is inappropriate. Note also that you should respect every student's physical space. Everyone has privacy and space needs, and our personal preferences regarding this may differ -- a general rule is that you should not touch or make physical contact with the students you are helping. "