Fire and Earth… this is always an interesting combination but it is up to you whether it is long-lasting or not.
Sagittarius is a sign that values freedom. Your Virgo wishes for a partner who is faithful, someone who will stay with him for a long-lasting relationship. Sagittarius does not appreciate these types of sentiments, and your Virgo may go as far as to call you irresponsible and childish.
Some more differences between the two of you : Sagittarius enjoys adventure and staying out all night, while Virgo would rather stay inside and build a peaceful and committed home. You are known for being a little extravagant (there’s absolutely nothing wrong with that) while Virgo would rather sit on money and disapproves of your spending habits.
You will, however, always be intellectually stimulated in this relationship. There will never be a lack of philosophical discussion, interesting debates, and sometimes riveting arguments. Your sex life will be rooted in your cooperative intellectual world, and it will always be thrilling.
Sagittarius and Virgo are often not meant to be soul mates, perhaps a short term relationship would work better for the two of you than something involving marriage.