No crossing swords.
When eye contact is made a high five must be given.
Which dude will recieve the blowjob and which guy will fuck her doggy, must be prederteremined before the spitroast.
This is to avoid the complicated situations when both males only wish to get oral from a less than average female, or when both wish to fuck a rare honey that can be conned into a spitroast.

If the males raise their arms towards each other at 45* angles and hold hands over the girl, the position becomes known as a sydney harbour bridge.
If a 3rd guy can somehow manage to fuck the girl in her other hole then this is known as a double adaptor spitroast.
If instead the 3rd guy joins the action by wanking over the females back or breasts, then the position is known as a lathe.