3.5 year old that they were going to the doctor for a jab? DS1 has 2nd MMR tomorrow and looking for advice on how to prepare him. When I was last with our practice nurse she said don't tell him why he's coming, he'll only fret, but won't he be cross with me for not telling him the truth? Is it better to explain that it might hurt for a moment but then be OK? Advice welcome, thanks!