It's my bday today (Sept 1) so this is the second one of it being ur birthday! He is a bit shy to go over to you and say happy birthday to you, so he'll just stick with following you and not speaking, when he gains up the courage he says he needs to say something and he says

"I-well I-um.. I-i wanted to s-tell you h-that I.. H-happy b-b-birthday!!"

He seems so embarrassed! The way he's stuttering like he never usually does is so cute!