Public Displays of Affection in High Schools?

Today, I kissed my girlfriend after walking her to her cl. It was just a quick little kiss. I was yelled at by a staff member shrieking, "No PDA!" This upset me exceptionally. Is there really any reason for teachers to do that? That was the 2nd time I have been hled for PDA and all I want to know is... why? It's not like we were making out right there in the hallway. It was just a little peck. I think that teachers need to be more concerned about themselves and their lives rather than what goes on in my life and what goes on between my girlfriend and I. Which is MY business and no one else's. Not the principal, not the staff, no ones but my own! If I want to kiss her, I am going to kiss her. They really think they are going to tell me I am not allowed to kiss my girlfriend because it will "effect my concentration in school"? How does that make sense? I am a student who can manage things in my life. I can keep up with all of my schoolwork and have a girlfriend. Plus, I'm on the track team. Each student is different and their minds work in distinct ways. What's next? Are we not going to be allowed to even be in a relationship with anyone at all?! Also, they can not tell me that I am going to do everything they say just because I learn at their corrupted facility. They can suspend me; do whatever they want to me because they damn well know that day I come back, I'm going to go up to my girlfriend and kiss her again. I believe this whole thing is unjust and I want your opinions on it.