<p>The first thing to do is realize that you likely don’t have a crush on the teacher, but rather that the teacher fits into some (possibly abstract) criteria you find “attractive.”</p>
<p>I can say with near certainty that you don’t know the teacher well enough to have a crush on his/her actual person, but rather that you are familiar with how he acts in front of his students. He/she has traits you find desirable in a mate, but is likely not special in any way.</p>
<p>Now that you’ve realized this, it’s easier to let the crush go and instead appreciate the person, enjoying but not desiring him/her. Sort of like Kant’s definition of something aesthetically pleasing: you find beauty in it, but you don’t desire it (that would be something agreeable).</p>