The sign for "ruin" also means "spoil" as in "spoiled milk."
The dominant-hand "X"-handshape is placed on top of the non-dominant "X"-handshape (both "X"
handshapes have the knuckle pointing forward rather than upward. The
non-dominant hand doesn't move. The dominant hand slides forward and
(usually) pivots up. The movement of the dominant hand is somewhat like a kid popping a wheelie on a bicycle.
RUIN / SPOIL:
RUIN: (side view)
Note: If you mean spoiled as in "spoiled child" use the sign
PET with an exaggerated movement and a
disapproving facial expression."
You can learn
Language (ASL) online at American Sign Language University ™
ASL resources by Lifeprint.com © Dr. William Vicars