You are free to leave the group at any time you want. Few choices we make have zero consequences.....especially when they affect others.
On a related note if you end up in that many bad groups (bad mouthing, misvehavior, ninja looting LOL) then maybe it is time to look in the mirror. The vast mahority of DF groups I have been in consist of a few "hellos" at the beginning and a few "gj ty" at the end. If you end up in enough groups of "bad mouthing" that this would matter I am speculating it may be due to an entitled/selfish attitude from one of the 4 members in your group....of which you are the only common denominator.
