I have known one 18 years old student who is senior dating with a teacher (24), and they both never got busted, except me. Now, I am just happy for them, they don't let people control their love, and I'm just impressed that they acted it professionally such as not letting anyone to find out/know.
IF you are single, and fell in love with that student, and he do same thing to you but you can't date him because of rules (basically you let people control you), which is really LAME.
WORK SOMETHING OUT FOR THE BEST.
