My friends joke

I was eating a packet of biscuit when suddenly my sister and my best buddies came to my class....
They were calling me for recess...
then they saw me eating the biscuit and my sister said
"Han I nak"
I said "nah amiklah"
"Thanx".Than muna said "Han Mak kau buat ke??"
"Taklah kitorang beli jer kat supermarket" I replied
When we were walking out of the class my sister said
"Aku taulah mak han tak bley bake tapi mak muna bley bake cakes because bapak dierkan bakri as in bakery"
Hahahahahahahaahahahahaha........sorryler muna