Question for a character in my novel?

[D]

Okay in my book, the main character is a middle child. He has a younger and older sibling.
Well sometime later in the story, he discovers that one of the already introduced characters is his half-brother. Neither of them knew. I want them to be close to each other in age, but I can't decide if I want the main character to be slightly older or slightly younger than the half-brother. It's not a huge deal, but I can't decide which I like more! Haha. What does everyone think?

 

[Azkaar]

Make the main character a little younger. So then maybe you can write that the elder brother is being rude to him or anything.