It depends. If you're booking a duo it better be from of the trusted agencies or at least someone who advertises here I would say, IN ADDITION to using your judgement.
I had a duo once and got robbed the 2nd time I called one of the girls out because the lady insisted on bringing her friend and while I was in the shower with the hot one the uglier one took not only the money I offered but also additional money I had in my coat pocket.
Besides that yeah it's more or less the same routine. Kiss kiss, light chatter, touch each other and take off your clothes? The one recently I just jumped on the bed with my clothes on and she was like "you won't be needing those." Oh yeah.
