If you are still studying, then just say you want to concentrate
on studies first. If you are working, just tell her blatantly that
you aren't interested. Don't get a girl to pose as your girlfriend,
it will hurt both parties. Not even if the girl says she doesn't
mind.
That girl may be crazy enough to suggest that she will only give up
if she sees you with your girlfriend, please don't follow her and
be that crazy and hurt yourself and others.
