T. wanted to ride the bike. So we did both: for the very first time, I took T. on the trailabike to the store with both panniers and we got groceries and came home. T. was cooperative the whole way: left his helmet on, stopped and waited for me when I asked him to and generally was calm and helpful. I wanted to get him some vanilla ice cream because we were out. Unfortunately, he is so stuffed up, it doesn't taste right to him. It is very sad.
R. took him out to ride further on the trailabike.
But I'm very, very happy that worked out so well. Also, very sweaty.