c'mon, grandma!

I overheard this sad exchange yesterday while I was walking home from work:

Older woman with walker, huffing and puffing to keep up with two kids, one around thirteen, the other around eleven, wearing school uniforms. Only the younger of the two kids spoke.

Kid: Come ON, grandma!
Grandma: (huffing) Now you slow down... you gonna have to wait... I gots to stop to buy me some-
Kid: NO! We ain't stoppin' at no liquor store!
Grandma: Oh yes we are. I gots something to get.
Kid: Come ON, Grandma! I gotta get home! We ain't stoppin' at the liquor store. (Pause. Then pleading.) I hafta get home to do my homework!

Grandma ignores him, pushes walker, huffing, towards the liquor store entrance. It made me want to cry.