Does he have bad memories of his relationship with his ex? Maybe your curls remind him of his time with her and that's why he doesn't like your hair curly.

I'm a good speller! My iPhone keyboard? Not so much.
Sulfate/non-water-soluble silicone free since 8/16/10
Northern VA
Med-coarse, normal porosity, low elasticity
Dye-free since 11/2010