I think he would be annoyed more so than disgusted, but still disapproving. Most men with normal T values abhor their own women mixing, and I think this is a natural, biological response.
A lot of things are a normal, biological response; however, you cannot reduce people to purely biological responses. Science has disproven this reductionist notion. Environment/learning account for a wide range of behaviors.
Anyway, I think it would be hypocritical of me to abhor my own race (white women) mixing with other men, considering my girlfriend is Cuban (and I am white). The funny thing is, is that she has lighter skin than me.
It would be an interesting study to conduct (not sure if its been done already): to see if men think it's okay for them to date outside race, but see how they respond if women of their own race date outside of their race. I mean, is it more socially acceptable for a white man to date outside of his race, but less acceptable for a white women to date outside of her race? Hmmmm.