I have this conversation with Eli several times per day, with different food types or toys involved:

"Can I have a mandarin please?
"Yes you may, here you go"
"Sorry baby - it's mine!"
"Share with baby please"
"No I don't want to"
"That's ok, I'll get baby some yummy pear instead."
"I'm sharing! I'm sharing! I want some yummy pear too please!"