What happens is like this:

Most of the time the guy has to chase the girl. When doing so, the girl will ask the opinions of her friends, if the guy fetches her the friends will say "this is an okay guy'", but if he asks her to fetch her during that period, the friends will say "how can a guy act like this". So if he asks her to fetch, most likely no deal lo.

After he has got her, if he starts asking her to fetch, the girl will think "last time you were so nice to me but now once you have got me you are changing!" So once the bar of expectation is set, it is hard to shift.