AOG
If you weren't a racist, then the comment about white genes wouldn't have occured to you. Seriously. There's no problem speculating as to why people seem to find mixed-race people more attractive, but if your curiosity on that issue was at the front of your mind, then you simply wouldn't feel the need to crowbar in a comment that essentially thinks 'white genes' are better.
And before you say it, that -is- what seems to underline that comment. If the 'white gene' is intrinsically more likely to cause attractiveness than the 'black gene', then that means essentially that 'whiteness' can make even a black more attractive. That is racist. I know that you probably don't think it is, but it is. The reason you can't appreciate the subtle differences is because you are a racist. I think you need to embrace that fact, we all know it.
And I agree with Gromit, it made me laugh.