Characters who try to sabotage other characters' relationships because of jealousy are SHIT CHARACTERS (and shit people/human beings in general). I submit for your approval the Student Council President in this manga. It's bad enough when it's across genders (like a guy sabotaging another guy to get a girl) but it's equally bad when it's the same gender. It's, unfortunately, a HUMAN trait but I've seen this trope in enough manga and it just needs to die. Take it out back and shoot it in the head then burn it with fire, please.