0% compatibility in terms of personality, 200% compatibility in terms of sex!! My brother's wife, who doesn't get along with me in terms of personality, doesn't want to hurt her infertile brother, so she asked me, her younger brother, to "cum inside her"! I inserted my dick to let her cum inside as she wished, and she came instantly! I gave her a little thrust and she came again! She acted tough at the time, but maybe it felt really good... She asked for as much cum inside her as she wanted!!