Are we suppose to feel sorry for the couples?

I don't believe so. Maybe the only one we could have any empathy for is the younger brother. The other three were not "good" people in the traditional sense and rather selfish. It sees odd that what happened in the shower was the first time since the older brother was with the new girl.

I agree with the exception of Allison Brie's character. The rest were just people making stupid and bad decisions. I kind of wish her character would have escaped.

Kind of a bore how everything turned out and we learn nothing.

I agree - when that Indian girl was running in the fog I said to my wife - are we supposed to be routing for any of these characters? Cause I'm not.

The moment the girl said "I've got a surprise for us~" and came back with drugs is where I lost sympathy for the characters. Then it just gets worse from there. The guy kisses his coworker in the hot tub, then again in the shower, and then they bang in the shower, all the while everyone is in the house... they really don't want us to feel sorry or root for these people.