Meet Zephaniah (2yrs) && Zayla (5days)

My son is rambunctious !! The only thing that slows him down is well NOTHING LOL.!! He loves his little sister , always wants to hold her. When she cries he whispers "it's okay " ... well I've noticed here lately that when I'm not holding babygirl he now wants to lay in my arms and he wants my kisses continuously . Before , my son could care less all he cared about was outside and toys lol. He seems a bit more sensitive .. is this normal ?? I fear I may not be balancing this very well .. i don't want my big boy to feel left out . I hate to think I'm not giving him the attention and affection he needs . What are somethings I could do to make him feel a part of this. I've heard some horror stories regarding siblings this young , I don't want to experience that . All I want is to see these two grow up in a living harmonious relationship .