I have an idea, treat your girlfriend to a spa day. They have facials and sugering for upper lip hair removal. Don't tell her anything about her hair problem, have a friend go with her and suggest that they try the sugaring on their upper lips. It would be the friends idea and your girlfriend might want to get rid of the hair but not know how to do it. I did this with a friend of mine and she had the hair removed and loved it. p.s. a lot of women are very aware of their facial hair problem but don't know what to do about it.