Elijah is your moms husband. You see him as a dad and according to him, he sees you as his own. Though it's apparent he goes out of his way to bond more with your younger half siblings, his biological kids.

He practically raised you, you call him dad, but it's obvious he doesn't see you the same as he does his real kids, and after you question it he lets out a sigh

"I do care for you, really. But those are my real kids, we have to bond without you sometimes. I mean, I'm not your real dad."