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."
Also see: TEASE
Notes:
A student asks:
"The signs 'Ruined' and 'joking/teasing' look similar.. are the signs truly similar? If so, does the sign change because of the facial expression?"
Answer:
The sign for "ruined" tends to do a different movement (from tease). The movement of the sign RUIN could be described as similar to a motorbike popping a wheelie. The dominant X hand slides / scrapes along the top / thumb-side of the non-dominant X hand and then the crooked index finger pops upward (while the base of the X hand continues sliding forward (still in contact with the non-dominant hand).
Also see: https://youtu.be/wiLwLKraAPk
Notes: