Well, first date is not an ideal situation to bring the subject up. You are just getting to know the person, mentioning marriage at that time may set off alarm bells because no one is ready for that. I think it's natural for most people to talk about marriage later on once they feel comfortable in the relationship.
Don't cry, don't regret and don't blame
Weak find the whip, willing find freedom
Towards the sun, carry your name
In warm hands you are given
Ask the wind for the way
Uncertainty's gone, your path will unravel
Accept all as it is and do not blame
God or the Devil
~Born to Live - Mavrik~