ROTJ: Lukes morbid curosity gets the better of him
From Create Your Own Story
Jabba waits for Luke to protest, but Luke seems fixated on the scene about to take place in front of him. Jabba laughs "Looks like this Jedi's mind is more corrupt than my own, I am impressed." The entire chamber begins to laugh with Jabba. Luke swallows hard as a hard lump forms in his pants.
Leia is on the verge of tears and calls out to him. "Luke! What are you doing? Make them stop!" Luke glances over at her, a dark gleam in his eyes. Leia looks away "what has happened to you!?" Jabba pulls the chain forcing her head up. "SILENCE SLAVE" He shouts. "From now on the princess's body will be shared be the entire assembly. Skywalker, you may stay, but you must wait until everyone else has had his share. Now give me your weapon."