Objective morality as a proper basic belief

[Little Henry]

So when you see ISIS blind fold 2 men having sex in each other and throw them off a building or when you see ISIS capture a 6 year old girl and rape her do you react and say  "that is wrong what they are doing, it just seems so obvious it is wrong, like 1+1=3 is wrong. But hang on, i am actually sufferring from a delusion when i think this. Evolution has fooled me into thinking it is wrong, it is not wrong, i find it udesirable, but certainly not wrong. Move on, there is nothing to see here."

I mean if OM does not exist, you should really react the same way when you hear these stories about ISIS as you would when you hear one of your mates eat a food you dislike...i mean, if taste in food is subjective, if morality is also subjective, why have stronger thoughts about 1 and not the other?

Is this how you react?

Seriously?  You're presenting your conclusion in the example of the ISIS fighters raping and killing as evidence that you and you alone are in position of the one true objective morality?  Isn't that bar rather low as a test?

So when you see ISIS do these things, it doesnt seem obvious that they are doing something wrong like when someone says 1+1=3?