In my experience, most massage places will be happy to do a 4 hand session. I have always asked a lady that I have a history with to bring in another girl she is comfortable with and let the party begin. Usually, at the places, I have participated in 4 hands everything doubles. Sometimes the house fee is either waived or discounted but the tip for both girls are not. Just ask, they will be upfront with you particularly if you are a regular.