But ??? Butt !!!

Harrison, my five year old is learning to read at school. As such he has a list of sight words that he has to learn. He was quite chuffed to find out that one of these words is but.
"Hey Campbell, one of my sight words is but. *snigger*
In an effort to encourage the correct use of the word but, I asked Harrison to compose a sentence containing the word but. In reply I got
"I've got a butt"

Well, I tried....