When I was at high school I got one of those rectangular bicycle puncture repair kit boxes and made a hole in the bottom at one end and put cotton wool inside then poked my finger in and poured some red ink over it. I ran up to the physics master and said something like "please help me sir", he took one look and with a horrified look on his face said "good god!", I then wriggled my finger, the result was I had to bend over in front of the class as he kicked me up the back-side.
Nothing but heaven itself is better than a friend who is really a friend. - Plautus