love match 
noun
A marriage based on the mutual love of the couple rather than social or financial considerations.There were still some in Westminster last week who suspected this was a marriage of convenience, a presentational alliance rather than a love match....
- The idea of marriage as a love match, where two minds meet as one, is a relatively new one embraced by our generation and as a result, is raising impossible expectations and leading to huge disappointments.
- Their marriage was both a love match and a political partnership.