The Pally refused all my subtle DM hints that he really shouldn't be part of an adventuring group with such an evil chap. The assassin, for his part, made sure to do most of his nasty stuff away from the party, the pally played the role that he was converting the unwashed masses to goodness and light.

Hey...if that's how they want to roleplay, I'm open to it. They were both warned to play their class or suffer the consequences.

So we get to a chasm spanned by a rope bridge. The Palladin says "Stay here, I'll cross the bridge and secure the other side to make sure everything is safe. Come across when I give you the signal."

So the Palladin (Kris) starts crossing the bridge. The assassin (Rob) turns to me and says "Is he about halfway across now?"

Me: "Yeah, he's halfway"

Rob: with total nonchalance "Good, I cut the ropes holding the bridge up on this side."

Kris: "WHAT??? You can't do that!!"

Me: suddenly finding this hillarious "He just cut one and is cutting the other...whatcha gonna do?"

Kris: "I grab onto the rope!!!"

Me: "Roll dex"

He failed miserably and plummeted into the abyss. Everyone laughed except Kris who was MAD!