I think we need to get past the "Race Loyalty" myth. It doesn't exist for any group. BW/BM are not "loyal" to eachother, they have proximity and accessibility to eachother. BM are seen as sexually desired by other women whilst a lot of men place BW lower on the attraction level or are unsure how to approach them
Due to the systems we live under, many see White people are a step up from their own race socioeconomically.
In regards to marriage, men as whole are moving away from marriage. For some reason, Black men specifically AA men in America and Caribbean Men in the UK are blamed for this