Glued to the spot
Definition 1 of 1
Pro Tip 1/3Surprise or Shock
Use this phrase when describing an extreme emotional reaction that stops someone from moving. 
When the verdict was announced, the defendant was glued to the spot.
Pro Tip 2/3Colloquial Usage
It's casual language, suitable for conversations but not formal writing. 
At the surprise party, she walked in and was glued to the spot.
Pro Tip 3/3Metaphorical Expression
Understand it's not literal; nobody is actually stuck with glue, it's expressing inability to move. 
Hearing the strange noises, he was glued to the spot in his room.