Come on say MOMMY please!!

I feel like I have waited my whole life to her my child call me mommy! Well since he is 18 months you would think that I would hear this!! RIGHT? Guess again. My 18 month old says a lot of words.  He says cracker, (like that is the easiest word to say?) football, touchdown, daddy, papa, and I don't even know what else. He repeats LOTS of words. He can say momma, mom but he doesn't say it in reference to me or at me. Just once in a RARE while he says it when he is whining. He definately refers to Don as daddy. So yesterday Brody and I are laying on the floor. I am trying to get him to say Mamma. 

Me: Say momma

Brody: BBBIIYYEEEA (in a very drawn out tone.)

Me: Say MOOOMMMMMAAAA 

Brody: BYYYEEE

Me: SAY MOOMMMMMMMMMMAAAAAAAA

Brody: FFFFOOOOOTTBAAALLLL

ME: SAY MOMMMMMMAAAA

Brody: Football

*exasperated sigh*