Probably because you waited until he played paper to play, you cheating scoundrel.
@Galapple, as I kid, I once shoved a friend over for doing that.
@Dephenistrator, as a kid, I once killed a friend and massacred his entire neighbourhood over doing that
@Siska the Khajiit, dámnit Itachi!
I'd shoot a twinkie with eyes too.
Once upon a time there was a village of squares.
Then some circles came along.
"Get out of town roundies" the squares said, "You don't belong here"
"Why?" Said the circles
"Because you're racist" answered the squares