At least for me, there is one sure way to tell if a guy is a jerk or not. The way I decide a guy is a jerk is by how I feel about him. If I’m attracted to him and I start to have feelings for him, he’s a jerk. If I’m not attracted to him and don’t have feelings for him, chances are he’s a nice guy. There you have it, I revealed to you the best-kept secret as how to tell the jerks from the nice ones.