I've seen a lot in life - not that I consider this to be one weird thing. I have an open mind. I knew a white fella who was turned down by white women due to his size - yeah, you can laugh as aloud as I did, cos he said 9in! He was the wrong man at wrong place in this life. I've lately heard of him being in a rel with a quite hot black woman. Ain't I happy for him? Course!
Now. What are the other reasons for a white guy dating a 'sista' as you say, apart from the attraction to the color, I don't know. Hope it's always good intentions. And there are plenty of examples in Hollywood, the music business, and big cities. Some black women love the 'soft' touch *grinning sarcastically*, the loyalty of and devotion by white men.
I've heard years ago how a white man was spoken of among the whites as he dated black and how the woman was mostly called a pro. But in a way, without them dating black we weren't dating white either. So it must be good for everybody. What I never heard of is a black woman cucking her black man with a white bull. That would be funny and a big curiosity too. But I ain't seen it all in my life.