Brand New

How about including that each dyad has a date night that the third person can't intrude upon? This way, the vitally important 1-1 sex can happen authentically rather than only when the third person bows out. Each of you are likely to behave differently when given the tabled offer and over time, this could grow into an issue.
This brings up a valid point of view. Thank you for bringing this up. It is very important that each couple grows their individual relationships.