My 11 year old cousin has a crush on a girl who's 13

He should develop approaching skill and win a friend. Suggest that he not use standard terms of endearment, but attract her on subject matters. He should make her propose to him without him proposing to her. That would make him a good flirt, where he can win more girls by their interest and not just asking for date etc.

He should start in such a way where she must not ask "why you are asking me?" ,,

Ask him to do some mock proposal to you, and you evaluating them...

He can try hitting her up accidentally and walk away a few times to make her notice him often. Like he does some act in front of her.. but walks away with a smile and sorry .. but not make any connection.. This is a method to register oneself into another's memory.

Let him go ask her out ..he gets rejected he learns don't punch above your weight he gets accepted he learns u succeed in only if you try
.so it's a win win situation

I had many crushes at his age. I used to pass little sweet notes to them. Teen girls seem to like that

that is sweet and he trusts u

How did you realize it was a crush?