What do you do when you like someone you know you shouldn't?

That's where self discipline has to be introduced, u have to explain yourself that,he/she is not the right person for you. consider that person is similar to people whom you don't spend much of your time with, frndship is not advisable, act normal wen u meet him/her, and alwys rember that you can not like him/her..tis can help u i guess..