I hate this. I am not sure what to call it, but I will call it sandbagging.
It usually starts something like this: You get together for a ride with a buddy you have not ridden with for a long while. Before starting he informs you that he needs to go slow because he is not in very good shape and has not been able to ride much. He did not eat well the previous day, and his wife made him do yardwork. His kid was sick and kept him up half the night. Maybe his dog died the previous week. The truth is that he has been going in to work early for the last five weeks so that he can ride an extra hour every week day, weighing everything he eats, and putting in back to back seven hour rides on weekends. So you start out slow. He gauges his fitness versus yours during small hills or accelerations and, if and only if he finds that he is in better condition, proceeds to kick the sh!t out of you for the rest of the ride, all the time exclaiming how he cannot believe how well he is riding.
It usually starts something like this: You get together for a ride with a buddy you have not ridden with for a long while. Before starting he informs you that he needs to go slow because he is not in very good shape and has not been able to ride much. He did not eat well the previous day, and his wife made him do yardwork. His kid was sick and kept him up half the night. Maybe his dog died the previous week. The truth is that he has been going in to work early for the last five weeks so that he can ride an extra hour every week day, weighing everything he eats, and putting in back to back seven hour rides on weekends. So you start out slow. He gauges his fitness versus yours during small hills or accelerations and, if and only if he finds that he is in better condition, proceeds to kick the sh!t out of you for the rest of the ride, all the time exclaiming how he cannot believe how well he is riding.