Confirming marriage to be what it has always been is not discrimination.
Changing the definition of marriage to suit a few involved in perversion is foolishness and will cause the fall of a society and culture. Look at ancient Greece.
Changing the constitution will not stop gay people form being in relationships, visible and public relationships that more and more are lasting longer than their straight counterparts. I would think it would be more important to look at the divorce rate in this country than to try and work what really is discrimination into the constitution, when it really won't change anything, but will have the potential to make so many more things in this country worse. If our constitution can ban a certain group from doing something, when it doesn't endanger anyone else, is a slippery slope on which I don't want to be.