Hitting..

Tessa

My 19 month old has started hitting me...and only me. No one else. How do I get him to stop? When I'm stern with him and say no thats not nice to hit mommy, he just laughs he thinks it's funny. I try not to yell and I feel like a spank on the butt won't so much as this age. So what can I do to get him to stop?? I want to nip this in the butt!!