This is a twist you can easily do with any role play activity to make the whole experience more interesting for your class participants.
Split the whole group into two teams, give half the role play for one team to read and the other half to the other team. Ask for a volunteer from the team that has the first half of the activity and ask them to start the activity. At any point you can ask him/her to stop and ask anyone from the other team to continue the activity. You can keep going back and forth between the teams. what makes this little twist effective is that all participants usually stay attentive so that they are prepared in case they are called to jump in.