Age Gap, Teacher-Student Relationship

I swear, not being homophobic but what d'you guys think of student-teacher relationship? It's prevalent when I was in senior high school, their age gap was pretty afar, and we were still minors that time. The admin of the institute was pretty cool with it, so the couple never really mind and showing their relationship to public. I wonder how their parents feel about that.

One of the teachers was actually living together with his student lover. They pretty much lived like a married couple; he was also the one paying for his school needs. Now, I'm in college, one of our male professors openly flirts with cute boys half his age. At first, I was laughing along, because I thought that's his way of entertaining the class. I was shocked that he was being dead serious of his feelings for those students.  It is said that our professor was the one doing the research of this cute boy, but he dropped it after being rejected since the cute boy was honest of his sexuality-- straight and a certified womanizer.

It's never really my business and I shouldn't care since I never genuinely cared for those people, but I always wonder why the school never really done anything about these incidents.