Prevent creampie overlays from stacking.

code/modules/food_and_drinks/food/snacks_pie.dm

@@ -50,7 +50,9 @@
 		H.adjust_blurriness(1)
 		H.visible_message("<span class='warning'>[H] is creamed by [src]!</span>", "<span class='userdanger'>You've been creamed by [src]!</span>")
 		playsound(H, "desceration", 50, TRUE)
-		H.add_overlay(creamoverlay)
+		if (!H.creamed) // one layer at a time
+			H.add_overlay(creamoverlay)
+			H.creamed = TRUE
 	qdel(src)
 
 
@@ -237,4 +239,4 @@
 	icon_state = "frostypie"
 	bonus_reagents = list("nutriment" = 4, "vitamin" = 6)
 	tastes = list("mint" = 1, "pie" = 1)
-	foodtype = GRAIN | FRUIT | SUGAR
+	foodtype = GRAIN | FRUIT | SUGAR