Seems like a lot of acting more than anything else. Girls are called into a room, lined up, legs open wide. Then the sorority start eating them out, and they have to return the favor. Or college hunks are brought in to give them a good shagging. Freshers all looking scared, weak protests. To refuse would mean no entry into the sorority and given a hard time (but not by cocks!) in the college.
Probabely all make-belief?