Should i ask him to call me mom?

My step son Diego is 1 and we get him at least 2 or 3 days a week. He loves me and always wants to be with me wherever we go! Always running to me. I love it. But when we take him back to his real mothers home he loves her you can just tell. But when hes older id like for him to call me mom, not really Jess. My hubby doesnt like his ex at all but he knows that that is the true momma. Should I ask my hubby if diego can call me mom too? that way when he starts talking he'll call me momma? I want to be his mother and i love him sooo much as if he is my own.