Instruct: Classify Amazon reviews into positive or negative sentiment
Query: MY SON HAS MULIPLE BRUISES ON HIS BACK!!!

My son's grandma bought this bike for my 2 1/2 year old and it is not safe. At first he tipped it over over time he turned just a little so we did not ride outdoors for a while. Later he seemed to be getting better at it, so we have been using it outside.A few days ago I noticed bruises on my son's back. At first I thought he fell on something but I have been noticing he is peddling really slow lately and today he complained that his back hurt all day. He has multiple bruises where the seat is hitting his back. Please do not buy this bike! It is not worth the bumps and brusies to your child.Kari