Alone in front of the Senate-house, Aaron delivers a soliloquy (a long speech that reveals a character's innermost thoughts to the audience) about Tamora's rise to power in Rome. Since Tamora and Aaron are longtime secret lovers, Aaron is hoping to benefit from Tamora's new status as Rome's imperial first lady. Aaron also brags that, since Tamora is basically his love slave, he'll soon be in a position to destroy Rome. (Aaron never really explains why he wants to do this.)
Chiron and Demetrius show up and they're in the middle of a big, nasty argument, which goes something like this: Chiron: "I'm just as tough as you are and I'm going to seduce Lavinia." Demetrius: "You're a wimp and I’m the one who's going to seduce Lavinia."
Aaron steps in and says Chiron and Demetrius are crazy if they think they're going to fight over Lavinia in public. For one thing, Lavinia's not the type of girl to cheat on her husband. Plus, Bassianus isn't the type of guy to stand around while two punks try to hit on his wife.
Aaron announces there's a way Chiron and Demetrius can both have Lavinia – during tomorrow's big panther hunt, they can take turns raping Lavinia in the forest.
Chiron and Demetrius think this is an excellent idea.