At about seven or eight years old I was one of several neighbourhood children to have a toy medical kit and we took turns using the various instruments on one another in order, simulating as near as possible our real experiences at the doctor. Last of all was always the syringe, use of which initially was a quandary for me. Whilst I wanted to give injections in the bottom, I feared that doing so would betray that I still got shots back there (which we all regarded to be childish).
When I was once playing patient and the one playing doctor said I needed a shot, the girl playing nurse resolved the problem by asking where. Both the question and the reply, "In the bottom", spared me the embarrassment of indicating it to be my usual treatment and excited me with the realisation that they were both accustomed to buttock injections. When the smiling girl told me to pull down my pants and bend over, however, I instinctively bent across her lap, thereby demonstrating the humiliating way I really got my shots.