Scales

I went to visit my mum last night, we were watching, 'Who are you calling fat?' on BBC One.

I said, "That reminds me, mum, our Sue has been on a diet this week, she wants to come and use your scales."

"That's okay," She said, "Do you think she'll be round in the morning?"

"Yeah, I guess so," I replied,

Spoiler:

"you can't lose weight that fast."