Champ Hardy is a recurring character in Season 1 of Wynonna Earp.
Champ picked on girls as a kid until Waverly Earp kicked him in the nuts. Their relationship must have changed at some point because according to Wynonna, Champ and Waverly were highschool sweethearts. Champ is a former rodeo star and now works as a ranch hand and handyman for hire.
They breakup in the episode Constant Cravings because he was being inconsiderate and didn't seem to understand her, or what the skull that Curtis left her meant. He wanted to "shut her brain off" and have sex, while Waverly wanted to focus on the skull and what exactly it meant, and why Curtis had left it to her. She had become tired of his inconsideration for her feelings and the situation she was in.
Champ dislikes Nicole either because he is a homophobe or because he's jealous of her relationship with Waverly. Or because of both.