Your crush may have left your online friend request on pending because he tends to take a while before accepting or denying a friend request from people that he doesn’t really know or isn’t comfortably acquainted with.
There may be a number of other Facebook friend requests that your crush has received since you sent yours that he is yet to accept or deny. Hence, you may not be the only one experiencing this.
It’s best not to wait around on him to accept or deny your Facebook friend request. He may or may not get around to doing it eventually.
However, you may be better off if you just started getting to know him in real life. This will also allow him to get to know you better as a person.
This may actually increase the likelihood that he will return to his Facebook and accept your friend request.