[ilovejoel]

So lately when my sister comes up to me like to help me on the laptop, Joel jumps up and kinda jumps at her(not biting) and wedges between us. When I tell him to stop and be nice he will stop and actualy start licking her.
Is this okay as long as he stops after I say be nice? Or should he not be doing it at all.
I don't know why he does that, she's his second favorite person ever and they play all the time. Me and my sister are really close so I would think he could sense it or something.
Any advice??