The gym, shoes and a plastic bag

My boyfriend and I decided to go to the gym tonight. Well his shoes were in a plastic bag that was sitting on top of the garbage can in the garage. Well he asked me to grab it which I did. We get to the gym and he goes to change his shoes and there is only one in the bag. So we look down the hall at the f and don't see it. Well he decides to wear his dirty shoes. We work out and leave. His shoe is not in the car. Once at home we see the shoe sitting on top of the garbage can. It fell out when I grabbed it. I didn't notice at all. It was me being blonde.