I suspect it's simply a stick he has chosen to use to beat the new lover. Vile and uncalled for, but that is all the underlying reason is.
Of course, one problem is still that many people still have racist feelings, particlualry in non suburban areas. You can make all the laws you like but all it does is generally silence them, the thoughts do not go away and, if anything, will fester away and become greater.
It is education, time and understanding, on both sides, that will eventually end this madness. To be honest I dont believe high profile reporting like this serves any purpose. The racists will revel in it and the anti racists will also take comfort. No one gains.