I don't know what just happened :/

so I'm 14, and today my bestfriend and I were talking back to my place from McDonald's. As we were walking a guy in a black car drives past dick in hand and is jerking off looking at us. I froze and then me and my friend decide to run. I cried and idk I'm just kinda in shock. I'm so disgusted with myself, makes me feel like maybe if my shorts were a little longer and maybe if I had covered up more it would've been fine I just don't know