Is it normal to have a sex fantasy about a teacher or boss?

Ever since i was about 14 years old I've had this on going fantasy of having a fling with an older male teacher after school in a class room. Or older male boss or supervisor in the back store room after work or something.
I'm not sure why, but that man in the suit who's got the power really turns me on, and even more if they're married or taken...
I just got a new job and I'm feeling like this AGAIN about my boss.
is this normal?