Age difference and relationships

So my friend has a daughter who is seeing an older man. She's eighteen and he's about twice her age. At first I had no opinion on the issue. I asked my friend what he thought about the matter and he wasn't quite sure himself. He let his wife take the lead in the matter (mostly) and trusted his daughter.

My niece got married to an older guy. He was twelve years her senior. I never saw that as a problem. Still, she did not pass the ole European rule of marriage. Now the rule is for men, and it goes like this: "Never marry anyone who is under half your age plus seven. He was thirty six and she was twenty four.... and in case you were wondering half his age plus seven would be twenty five. But it is a stupid rule because if they waited two years she would be compliant. It's just playing with numbers.

Deuteronomy 22:10 says  "You must not plough with ox and donkey together" ... another translation says that you must not yolk them together. The apostle Paul refers to this scripture when discussing a faithful person marrying a non-believer. I was speaking once to a Seventh day Adventist who referred to this scripture being about people with any major differences in their lives. She was saying that  people from different:cultures, religions, beliefs, races, financial or social backgrounds, or people with large age differences, should not marry. That was almost twenty years ago, and I still don't agree with her. In the West Indies it is quite common to find couples with all of those differences who have lived happily married lives. Sure they would have had problems, but all marriages have problems. The test of a mans mettle and a woman's strength is riding through the storm while still showing love. Perhaps these couples do well just so that they could spite their detractors... no that's silly. They do well because their love conquers the barriers that life throws in front of them.

I don't know if I would or would not approve of an older guy dating my daughter. In discussing the issue with my friend I asked him a simple question, which I think should be the overriding factor: Is the guy a good and practicing Catholic? It turns out that he is indeed a good and practicing Catholic. Praise God for that!