How to make my character more real?

In the story I am writing my leading male character is grouchy and sarcastic. Of course the girl falls for him but he never changes through out the book and never devolopes feelings for her. What are some things a grumpy, scornful character would do? and what are some good traits that he could have that would not... show more In the story I am writing my leading male character is grouchy and sarcastic. Of course the girl falls for him but he never changes through out the book and never devolopes feelings for her. What are some things a grumpy, scornful character would do? and what are some good traits that he could have that would not contridict his personality in a Mary Sue way?

Thanks :)
4 answers 4