I've given up group riding long ago. Especially with people a barely know. Too many close calls or incidents.
One group ride first corner person goes off roading.
Then on another, person on a gsxr goes down twice. 2nd time he cooked a S turn.
The one that really pissed me off was a friend of a friend. I was mid pack behind a friend who was riding overly conservative then his friend tried to stuff from in inside of the corner and he ends up going off road but kept it upright. After that i checked out and hung with the leader. Later in the day his excuse was he thought I was flagging him by. Wtf!