Steven is a lot like his mother and father in terms of his ability to surprise us. When we first meet Steven, he's a child. He discovers Matt in Celia's little house. He takes charge and helps Matt after Matt injures himself by falling on broken glass. However, Steven's attitude towards Matt changes rapidly as soon as he learns that Matt is a clone. Steven is never unkind towards Matt, but he starts to keep his distance. So when Steven, now an adult, turns Matt over to El Patrón in time for some organ harvesting, Matt is shocked. And so are we. Take a look:
In all this time he'd thought Steven and Emilia were – if not his friends – not his enemies, either. He admired Steven. In many ways they were alike.
"Take him," Steven signaled to the bodyguards. (22.115-16)
In the end, Steven can't quite rise above his upbringing. He chooses to remain loyal to the oppressive system El Patrón has created.