That's all that any opposition to so-called "interracial" dating or sex is, the mind interpreting an outside presence as a threat. For whatever reason the _________ woman should not be there. For women it's because they or their friends have needs that could be met by the same man. For men the threat could be seen as an affront to their masculinity. In both instances, it places the male and female on notice that they're not as competitive as they think are.
Generally speaking, when I'm out with a man, I'm focusing on him and don't notice if other people are staring or not. I don't frankly care if they are, my sex life is my business and no one else's
The only times I've ever garnered stares were at work. When people see you smiling, laughing, having an good time with a co-worker, their curious to see what's going on between you two, with many assuming that your "hitting that" which isn't the case most of the time. I have never gotten an evil stare from a black woman or a white man when out n about. Typically each group for the life of me always assumed that I only like white women.
Haven't gotten a lot of stares that were angry. Got stared at when I was with the man holding hands and walking around in my city... but that's probably just because it's rare to see non-white couples around. Also, probably because not only were we not of the same race, but we were also both using sign language Grabbed the ex and kissed him when we were walking down the street here in DC. Not a little peck, but a light make out session while sitting down and waiting for the bus. The sociologist in me was curious of reactions it might get, but no stares. They were probably just thinking, "ah, silly Gallaudet university kids"