Should i keep physical relation with my girl friend?

I am not married. i am still studying in college. i am in a relationship for two years. i want to be in a mild physical relationship with my girl friend. but she is not having the same mentality. she wants everything to be done after marriage...but i am not sure if she will be interested after marriage either...what should i do? should i keep poking her to meet my desires or should i stop all physical relationships until she realizes???? plz hlp....