Tammy works on a plan

Tammy gets up, showers and dresses before Beth and Robert return.
They both give a complete report on the classes they had attended.
Tammy then tells them she wants them to help her trap a teacher. Mr Eden their English teacher was kind of cute. Tammy decided he would do for starters.
The next day after the English class Beth and Robert help corner Mr. Eden and Tammy uses the book to control him.
All four of them return to Tammy's room where Tammy orders every one to undress.
Once her three slaves are naked she then has them undress her.
She then has Beth suck Mr Eden cock. While Robert goes down on her. Mr Eden cock is thicker than she expected. How to procede should she fuck Mr Eden while Robert fucks his sister or visa versa. Or should she take on both guys and Beth all at once?